MTN *********

I've been an MTN subcriber since 2007,my MTN contract expired in July and decided not to renew it, Since 10/07/2015 I've been struggling with MTN for my contract to be migrated to pre-paid and seem to be dealing with *********** consultants.I have not used the MTN SIM card since end of August and notified them of the migration but yet they still trying to get money for my bank account . My last payment to MTN was in September. Two months later Mr james Mpohale from credit management informed me that I was required to pay R787.80 for my account to be closed another week later Slyvia Makgopa from the rentention office sends me a mail that i am required to pay R532.80 as my account is in two months arrears. How is this possible when i've not used the sim and requested for my contract to be migrated in July? Why should I be paying as i've paid my contract in full and if you check the records I've not used your airtime or data in last two months? The ethics and principles of MTN operations in this case are highly questionable and I would like to speak to someone that understands whats going on before any extra money is ********** from me. herewith my reference numbers [#10782