Over-charged in advance

<p>2 years ago I renewed my contract with MTN for 24 months starting 3 March 2015 and ending 3 March 2017 i.e. 24 debit orders later (March 2015 to 28 Feb 2017)</p> <p>I was issued with an invoice for subscription fees for the month of March 2017 in advance even though my contract expired on 3 March 2017. I requested for my account to be ported and changed to pay-as-you-go on 8 March 2017. The following week my number was ported to Telkom.</p> <p>MTN attempted to debit my account for a full month's subscription at the end of March 2017 and I reversed teh debit order. I tried to phone MTN, but since I am not technically a subsciber or a pay-as-you-go customer I can't get past the automated answering service. I proceeded to email them to contest the bill and was simply told that the full amount is due even though I only received 8 days worth of service from them for the month of March.</p> <p>It is now 3 months down the line and to date they are still attempting to debit my account every month for services not requested, received or agreed to.</p> <p>I have offered to pay for the 8 days worth of subscription fees for March 2017 plus my usage during that period -according to my calculations this amounts to R101.94 but have not received any explanation other than "you are liable for the full amount"</p>