Worst repairs shop and workmanship ever

It has been 3 months since my car has been at Renew-it Edenvale, and it has gone from bad to WORSE!!! My car has been taken back about 4 times now for them to repair the initial accident damages they had to make, mind you every time I get a call saying that my car is ready for collection I get there with the same issues still there. Last week I was told my car was ready, only to find half my boot is not there, they (so called) repaired a light that had no issues at all and left the one they glued on, incorrect *****s used, alignment issues, over polishing, missing number plate, broken parts fitted and the list goes on... and they say they have a QC department??? If i wanted to take my car to a back shop I would have done so. Renault SA - please school me, what is the criteria for approving your Suppliers????