Bad service at a branch

the complaint is with MTN store in Hammarsdale Junction. my mom took out a contract at Pinetown branch when she went to Hammarsdale branch they told her they will not help her she must go back where she took her contract. last month when she went to pay her subscription she she was not a given a receipt and no reason was given to her. this month when she went to pay she was asked to put her card to pay without her information. when she asked what was happening, the lady then refused to help her.