Toyota Escondido

Took my car in to Toyota of Escondido because my engine was overheating. Checking things out, we felt it was just the thermostat. They called an hour later and said, "We found the leak. That's why you've been losing fluid. It'll be an extra $500." Huh?? There was no leak, we weren't losing fluid. Told them to just replace the thermostat. They objected, but it's been fine since, no leak, fluid level's fine. HOWEVER, when we got the car back, the check engine light was on, the VSC lights were on, weren't on before, haven't gone off since. Plus they must have torn one of the black duct things, as now it's all wrapped in black tape. Take your car ANYWHERE but here!