Continous bad service to elderly lady

My mother is a 78 year old lady living in Brandfort in the Free State, 60km outside of Bloemfontein. She upgraded her cellphone Contract December 2013 and upgraded to a Nokia Lumia 520. About 8 months into her contract, the cellphone started to give her problems and eventually did not want to go off airplane mode. She then took the phone into MTN at College Square in Bloemfontein where they told her that they have to send it in for repairs. She waited a day short of one month for the phone. During this period the lady who is the manager at that branch told her that they said she is going to get a new phone. She eventually received her same old phone back, and they said the replaced main board. <br> My mother got the phone back and within a week the phone again just switched off for no reason and did not want to charge properly. So my 78 year old mother drove 60 km again to Bloemfontein to take the phone back because it was not fixed. <br> They took in the phone again and send it in again for repairs. On Friday January 2, she went back to get the so-called repaired phone back. We filed a domplaint with Mtn, but they have not done anything upto today