Poor Service Continues

Its been more than 2 months that my Cell Phone was reported faulty with MTN. The phone was eventually seen by a repair centre in Durban although it was still under the 6 month replacement warranty. The phone was returned with comment: Unit was rejected as software upgrade solved the problem. When putting the device on, there is an immediate notice that the software needs to be updated from Current version: PDA:OG8 / CSC:OG8 / PHONE:OGE (XFA) to Latest version: PDA:OH5 / CSC:OH5 / PHONE:OH2 (XFA). Further, the phone was heating and freezing. On connecting the phone and merely trying to restore my data, the phone was hot again. At this stage, I am unable to speak to the line manager who was assisting me and I am expected to make do with this. this is not acceptable, and now wish to cancel the contract.