damaged car & dishonesty

appalling customer service. taking my car for standard servicing, they scratched my door lightly. I asked for them to repair. they said they would call to make a new appointment. They never got back to me. I had to follow up with them for 4 months. all the time they told me they were going to give me a call back, never did. After 4 months I eventually managed to get an appointment there -- I had to arrange something, because they could obviously not provided a courtesy car... otherwise my car would still not be fixed. So they indeed fixed the door, but when I fetched my car, I noticed a massive bump on my front bumper. They said it was not them, that we must have brought it with the bump already. Sooooo twice in a row they managed to damage your car... not to mention their complete dishonesty. Now I probably will have to wait another 4 months before they fix the bumper... I really cannot explain how clumsy and bad they are. but surely, they will never see my car again after this. they just do not care about customer service, and they are a bunch of *****.