Took my 2010 ford fusion for an oil change and alignment. They tried to sell me a transmission flush when i had already had one done. Do shops just look at mileage? Anyways, as i was driving off I say the wrench service light was on so i turned around and took it right back. The tech that worked on it said he couldnt take it off. He tried and tried. Than the manager said that in my car that light is for a power train malfunction and that the light was already on. I know for sure it wasnt. And they want to charge me for a diagnose as well. Therefore im riding with a service light on that was on before. Should I be worried about anything? Should i report it to the shops corporate email to have some type of proof if something goes wrong? What is that light for? To me it seemed like they didnt know what they were doing.