Made arrangment - MTN did not follow through

My MTN account is supposed to be a fixed monthly amount, yet they deduct huge amounts directly from my bank account. When I stopped payments they cut off my phone and handed account over to lawyers. when trying to phone customer care service received is very poor and inconclusive, especially in the time when MTN had their strikes. When contacted by the lawyers to pay I made an arrangement to pay the outstanding R1350 once off by bank debit order to be done on 2December2015, they said that my account will then be reinstated. as of today the 10th of December 2015 the amount has not been debited from my bank account. I was also promised that all the information discussed would be emailed to me - it was not. I know I am also in the wrong, but even when trying to fix problems the service received is poor