Horrible Service from Desiger dent

I took my car for bumper repairs 2 years ago, to Designer Dent in Northcliff the bumper was re sprayed and the car was ready in a week. When I went to collect the car there were few scratches that were not repaired and they just did quick fix with the paint. A year later the paint on the bumper started cracking and when I took the car back to them because they said they have a lifetime paint job warranty but that was not the case they were very dismissive and told me that it's not their fault. So they are not going to fix the car if they fix it I have to pay again. They told me they fix porches , Mercedes and Bms and my car is nothing. So I left it like that and I decided to Let it go. As we speak the paint is continuing to crack and my looks horrible. And I will not recommend anyone to go to designer Dent