A supplier mixed up fuel at the gas pumps at Walmart on Old Jacksonville in Tyler over Memorial Day weekend, leaving customers with hefty expenses. The diesel and unleaded tanks were swapped.

"Filled up my tank, and drove about two blocks up to Rice, and my car died," said James Fish, telling the story of how he started his Saturday morning, unexpectedly ending with his car being towed.

He suspected foul play at the pumps, but took his car to a Toyota dealership for a second pair of eyes.

"The tank did have diesel in it, and they would have to drop the tank, clean the engine and then reinstall it," he said.

That process alone cost $550.

He and his wife Karen said they filed a claim with Walmart immediately after learning about the gas mix up. On Wednesday, the couple said a Walmart representative told them they would have to pay for all repairs up front, and then send in receipts for reimbursement.

But that's an estimated $1,500 they said they don't have.

"I don't have the money to get it out," he said. "When am I going to get my car back?"

Walmart sent a statement to CBS19 addressing the problem.

“Last weekend, our supplier mixed up the fuel in our diesel and unleaded tanks at a Walmart in Tyler, TX. We shut down the pumps as soon as we became aware, and we immediately worked to purge and clean the lines. Service to our customers is a top priority and we apologize to any customers who were impacted by this. If you were affected, please contact store management so that we can work with our supplier to address your concerns.”

Looking at comments on Nextdoor, an app giving information based on GPS location, dozens chimed in about the gas mix-up.

Kevin writes, "Took it to Toyota, and they said I was the third person to bring my car in…they quoted me $500 for the fuel draining."

Another comment from Shelly reads, "They advised us not to drive it until a mechanic addressed the issue."

"We've had several people call with that problem."

Owner of Stewart's Donnybrook Automotive in Tyler, Gary Stewart, said to take your car to your local mechanic or dealership.

"You don't want to just keep shoving gas in it to fix it yourself," he said.

Out of pocket expenses vary, but Stewart said you'll pay between $400 and $600 to flush your tank.

As the Fish's look at that receipt one more time, they say they can only hope Walmart will stick by its word.

"$32.60 for a tank of gas that has given us much grief and hours of stress and strife," said Karen Morris-Fish.