Incorrect Billing

My contract was taken over from Nashua Mobile and suddenly I started receiving huge bills that were deducted from my bank account via debit order. I have sent numerous emails to [Email Removed] that are repeatedly returned, I have tried calling the call center but after holding for up to 2 hours I have then been cut off and I have been into 2 MTN shops both of which were rude and unhelpful and were not willing to assist in solving my account query. I am a pensioner and I cannot afford the huge bills. I am extremely dissatisfied with MTN and no longer wish to have a contract with MTN. I will forthwith cancel my debit order and make a case of ***** against MTN if they do not correct my billing. Mrs N J Prior Cel: ***