BMW NOT GETTING BACK TO ME TO FIX MY CAR

I took my car to kunene brothers on 5 February 2015 for service and to fix sound coming from boot & suspension when reversing.On collecting my car only the service and the boot had been fixed but suspension sound had not been fixed. Boot also had been fixed but now when i open it i can see the springs and foam.I complained via the service feedback & i got a call that Kunene would call me 2 give me a courtesy vehicle whilst they fix my car. A week later they called and asked me 2 come in so their workshop manager would drive the car . I went thru & he drove it & came and gave Ben and Mark report that there was a sound in suspension, the workmanship in fixing the boot was poor as well as a problem of the Display unit switching off for hours at a time. Ben then promised me that when they get a courtesy car for me they would call me back to come leave my car. I waited for a week & no one came back to me. I then phoned Ben and he said he would call me after easter as there were no cars available so i said ok. After easter i never got a call so i called back 2 weeks after easter and again got another promise. I have now been calling every week and now we are in May and still nothing!!