pathetic service!!

I sent my cellphone in for repairs while its still under warranty on 13th January 2015. After trying to locate my phone 2 weeks later nobody could tell me where my cellphone was after trying to call the repair centre for more than a week and finally got through they informed me to have my cell phone repaired it will be r1599. I rejected the quote thinking my cellphone will be sent back to mtn, only to find out they will not release the phone unless I pay a rejection fee of r330 which I was not informed about!!!..I specifically asked the consultant is thetr any fees involved and she said no.. I refuse to pay the money cos I was misinformed and they refuse to let my phone go..!! Poor service all and all and I constantly webt to the store waiting in line for 20 minutes only for them to not know where my cellphone was and not inform me of any penalties I should pay!!!