Car went in for a altenator repair and was bumped

I took my car in to Flip's Auto Electrical in Sasolburg. He had to replace the alternator on the vehicle. First of all he wanted to sell me a brand new alternator and I refused and said he had to repair mine. He done so and after 1 week my car was fixed. I went to fetch my car on the Saturday and when I got home my car made a huge noise. The fan belt are slipping on the pulley's. I phoned him and he asked that I must bring my car back on Sunday in order for them to get it fixed. I did so and then I shown his assisted Edward that my car was bumped by them. My car was fixed again after they sprayed anti slip or what ever on it but after I start it the next morning it still do the same. I phoned him time after time and every time he have an excuse. We finally had enough and send him an sms informing him that we are going to report him if he are not going to get our car fixed. I phoned him today, 09 March 2015 @ 10:50 and he said if we want to report him we can and every time he have an excuse for what I tell him. I said to him that his assistant knows what is going on and that the anti slip is not working. He quote which I received as well from the panel beater was R 2,600.00.