Billing Department unable to Reconcile Account

I gave notice and ended my long running MTN contract at the end of November 2014. MTN sent reference numbers, confirmations and farewell messages. I ported my number over to another Service Provider. I then continued to to be debited for 3 months afterward. I phoned, emailed and went into MTN stores to try sort this all out. MTN have eventually stopped billing me, and have refunded some of the money owed, but have yet to act on a final account reconciliation which apparently indicates that they owe me money. I have sent numerous emails, and have had responses stating that the issue has been passed onto various departments. 6 Months on, and it still drags on. Could somebody from MTN please finally do something about this? <br>