Horrible customer service about faulty new handset

My contract was due for an upgrade on the 1st of January 2016. I went for the upgrade on the 2nd of January, to the MTN Store in Checkers Hyper, Fleurdal, Bloemfontein. After upgrading, the cell phone I received was faulty, giving an error message when dialing any USSD code. <br> <br> I returned to the store on the 3rd of January to get a new cell phone based on the OBF warranty. I was told that this error does not warrant an OBF replacement and that I should take it to the repair centre. I went to the repair centre, but I was told that if the cell phone was booked in for repairs, it voids the OBF warranty, I should take it back to the store because this error does warrant a new cell phone. So I went back to the store, spoke to the store manager and the area manager who both still absolutely refused to do the OBF, they said I had to book the cell phone in for warranty assessment.<br> <br> Not knowing what to do further, I booked the phone in, being told it would take 7 working days. After two weeks and SEVERAL phone calls and visits, I still had not received the phone.<br> <br> It is unacceptable that the customer should carry the responsibility of a faulty, brand new handset, and not get any feedback.