Bad service

I took my car for repairs and to cut long story short, I've been waiting for them to give me a call from April as there were dents that I saw after repairs. I went to them as more problems were seen. But the main issue is now the replacement of the locknut that got lost by them. They promised to come back to me as one wheel is without a lockout. These wheels are expensive ie Mitchel 17 inch but I have to call them now and then but they have called me to fix the problem. I'm scared the wheel might be ****** cos it's visible that the locknut is out. I'm tired of calling them and or going there ,petrol is expensive. I'm starting to doubt the service done to the cars as more wrong was experience than right.Can I have my locknuts replaced and dents be fixed please.