Bad service rendered while they are at fault

I notice MTN has flagged my profile, after several months desputing one of my contract which was cancelled and i was still billed for it and have been paying that account for 8 months.

Hence i requested MTN to credit that refund back to my account then i settle the difference.

Till today MTN has not done or really looked into the matter. MTN legal department was alerted in this regard, instead i was rudely treated and threatened that i will get such demands which are now being presented.

I am not going to be de*****ed by MTN until they rectify their mistake, and credit back the 8 months ive paid then i will settle the balance.

Can anyone who is dealing with client service BA***