Poor services

I have a concern about my phone, which was taken in for repairs. I was having problems with my signal, not receiving most phone calls, but everything else was working fine. I booked the phone in at the mtn store westage mall western cape branch, the phone was sent to the repair center. I was informed that the sim card reader was defected, and will cost me R2015 to repair. I decided to cancel the quote. the phone was sent back to the store. i collected the phone on the 7th of March 2015. Once at home i inserted my sim, but the phone was not reading the sim, i took it back to the store, and to find out that it doesn't read any sim card. A email was sent from the store to the repair centre. I have yet to get a respond from them. My biggest problem is that the phone was in better condition before it went to the repair centre. Im now sitting with a completely broken phone , which im paying for. I then made a complain on mtn site, its been 5 workings days and i have yet to get any feedback.