I dropped my 2015 Hyundai Elantra off for service ...

I dropped my 2015 Hyundai Elantra off for service the beginning of November. I needed to buy new tires put on my car as well as an oil change and an inspection sticker. I was away at a training for my job November 5th-9th and was told I would be called when my vehicle was ready to be picked up. I get back from my training and still no call. 2 weeks go by and still no call. Now we are in December and finally today I get a call saying my car has been done and they need the loaner back. They offered to have my car driven to me and they would take the loaner back since I couldn't leave work. I go out to look at my car and there is a HUGE DENT ON MY DRIVER SIDE DOOR that was NOT THERE when I had dropped my car off. I called the service manager and told him I am not taking my car in that condition and that is completely unacceptable. He told me if I don't send the loaner back that he is going to call the police.
I haven t even gotten to the best part yet. My sons father is the general sales manager of the dealership. Anthony Coccia. That s how the dealership treats the mother of a managers son. Imagine how they ll treat a random customer who means nothing to them. Good luck.