Cell C - new device issues

I've taken a contract with Cell C - Rosebank store for a Samsung S4 mini in December 2014. In about February 2015 I started experiencing problems with the signal on the cellphone. I lodged a complaint with the Cell C store in Rosebank where I purchased the device. I was asked to complete the signal investigation form. I was contacted by the call centre and told to put my simcard in another cellphone to test the signal. The other cellphone worked perfectly. I then went back to the store and they took the cellphone in for further investigation after 2 weeks they called to pick the phone up and said it was beyond repair.<br> <br> I explained to the agent in the store that I cannot pay R260 for the next two years for a product that I cannot use. According to the call centre I was informed that my cellphone falls under warranty if problems occur within a three month period and that I should receive a new cellphone. They have now sent the phone back to the repair centre. I have called the store on various occasions since and have asked to speak to the manager. No one has called me back to give me any feedback.