Contract cancellation

I have been a visiting MTN stores to clear my debt, but they could not help, finally after few months they gave me MTN legal email...I sent the email to legal, but still there is no response this time they are increasing the debt, for the data they do not even send to me...

Please help i want out of this ..I want to pay them out and end our relationship..

I even sent email for them not to renew my contract, because I know they have tendency of renewing our contract without our consent.