I heard about a guy who had it happen to him. He called out the shop on the oil switcharoo and got a refund. But he wasn't happy about being out the 5 qts of oil he bought. So later that evening, he drove over to the shop with tools and did an oil change on his car in the parking lot right in front of the shop entrance. I drove by and saw the results the next morning. He didn't bother to use an oil pan when draining the oil