cell c pathetic service

over charged on my data contract. called 2 weeks ago to complain. passed all the security questions. put on hold foe about 30 minutes and then cut off and could not get through again. called again now to complain about the over charge but told they could not help me because i did not answer the questions correctly. all my information is stiil the same but they refuse to tell me what information i am providing incorrectly. told to go to a cell c store but when i go there they call the customer support center and we go in circles again. i will never deal with cell again. absolutely pathetic. not surprised that they are in such serious financial difficulties