"I feel like I've been robbed," homeowner Jacqueline Lyons told ABC11.
"Why was I being charged for something that I didn't need?" asked homeowner William Bullock.
In an exclusive ABC11 Eyewitness News I-Team investigation, we spoke with four homeowners with four complaints about four different Triangle area Lowe's stores.
And we also spoke to two subcontractors who showed us what they said was evidence that a contractor hired by Lowe's was keeping hundreds - even thousands - of dollars worth of excess materials from jobs.
"Being greedy, that's all I can say it is: greed," offered subcontractor Travis Byrd.
Besides the contractor hired by Lowe's, the customers we spoke to also pointed fingers at some Lowe's store representatives. Each said their project started with a store sales rep coming to their house.
"Lowe's sent out a roof expert," said Bullock. "I felt more comfortable going with Lowe's than going with an independent contractor that would be here today and be gone tomorrow."
But all four homeowners now say they're questioning the trust they put in Lowe's.
Constance Wright told us she wanted to know why there were eight leftover boxes of siding from her job.
Shirley Dark didn't think anything was wrong until we told her a worker on her job claimed she was out 10 bundles of shingles.
Jacqueline Lyons said 14 bundles of extra shingles that she paid for disappeared. She said she demanded answers from her Lowe's sales representative.
William Bullock wasn't happy either. He said he caught his Lowe's sales representative taking five rolls of roofing materials without his permission.
"Each roll of ice and water barrier he took from my property sells for $65. He removed five," Bullock claimed.
It was all material that the homeowners say Lowe's sales reps ordered.
"I think that's excess and especially if someone in roofing knows what they're doing, and this gentleman claims he's been in for years," Bullock offered.
"There's no way in the world someone's math can be off that much - not for 16 bundles. That's a lot of bundles. I think it's been done deliberately," said Lyons.
The subcontractors who spoke with ABC11 agree. Both said they saw what happened firsthand.
Travis Byrd said he worked for a Lowe's contractor for more than two years. He showed us roofing material spread out in three different locations that he said was leftovers from jobs he worked on - materials he claimed his boss told him to hide.
"Right there is the yellow tag that shows it comes from Lowe's," said Byrd.
Byrd and another worker - who asked not to be identified by name - said the problem is widespread. They claim it's not just materials, but also labor and other costs.
"He measures the job and then adds overage to it. There's at least six bundles of shingles added extra, two squares extra," said the second worker. "So his labor price is $85 a square is what he gets from Lowe's for installing. So at least 160 to 170 on every job he's getting for doing nothing."
And they both say estimating the amount of material you need for a roofing job is a fairly exact science.
"You can over estimate one bundle of shingles just to make sure you're going to have enough, but there's no reason to estimate 13 to 14 bundles extra," said the second worker. "It's all done by square foot."
"When you measure a roof, the square footage of it, you divide by 100 and that tells you how many squares of shingles you need. So it's pretty cut and dry how many shingles you need, you can get it a lot closer than he's been getting it," he continued.
"He" is the man they both worked for: contractor Stacey Parker. Parker denied the allegations when we caught up with him on another roofing job for Lowe's.
"Is it a Lowe's sales person who orders the extra materials?" asked investigative reporter Diane Wilson.
"I confer with sales, with the PSE, which is the Project Specialists on this, and we come to an agreement on what happens. And sometimes they go with my figures and sometimes they don't go with my figures," said Parker.
We talked to Parker about what happens if there are extra materials.
"I've had some, um some of the PSE have said: 'Don't return anything. Do whatever you want to with it,'" Parker responded.
Parker also questioned the credibility of the two subcontractors who spoke with us.
"Two particular guys that are disgruntled employees that are trying to take me down," Parker said.
Parker also said that if any materials were taken, the workers did it when he wasn't around.
We've approached Lowe's with the allegations made by the customers and subcontractors. In a written statement on September 8, the company said that they have reviewed the project files and conducted an internal investigation for each of the installations brought we brought to its attention.
"We are confident there was no intentional effort to over-order or to improperly remove material from any of these homes," said Lowe's.
Lowe's also told us previously:
"Because roofing and siding jobs involve unique color and product elements for each job, any material left over after an installation has little to no value to anyone except the customer because of the difficulty of matching product attributes."
As for the allegation that sales reps are padding the projects for contractors, Lowe's said:
"Lowe's installers are independent contractors and are paid by the complexity of the job, not by the amount of material they install. In addition to the lack of motivation, given the competitive nature of the market, each job has a number of checks to ensure customers are receiving the best price possible."
But the customers we talked to said they don't buy that.
"To think that people take advantage, especially senior citizens, and that is so sad," said Dark.
"My husband died. I'm a widow. I'm here all alone. I don't have money to give to anybody," offered Lyons. "I'm sure they did this to someone else besides me."
"I feel like I'm not the only one. I feel it's more wide spread," said Bullock.
And the two subcontractors don't buy what Lowe's had to say either.
"They're paying for stuff that's not getting done," said Byrd.
"They would have gotten my mother, my grandmother, or someone else's grandmother," claimed the second worker.
Constance Wright, William Bullock, and Jacqueline Lyons all got refunds when they complained to Lowe's.
And, the company told us: "Customer service and complete customer satisfaction are always our first priority."