bad service

Bad service- My friend had sound installed with them last week paid R7500.00 they told us it will take 2 and half hours to install it by the time we got back they where still busy and told my friend he needs to pay another R170.00 we paid it and never received a receipt we waited about another hour my friend was not happy and he told them the sound is not what he wanted. We left by the time we got home the sound was worst then the sound he had in before. He then went back in the week they reinstalled it drove to Bedfordview by the time he got to Bedfordview the speakers burned and wire also he had to go all the way back to Myfair to let them fix it again, Today the sound just burned again. I tried calling them asking to speak to a manager I got put on hold then I was cut off. It is a lot of money just to let it go