Billing Issues

I seriously do not know what to do now this is my fourth complaint on helopeter and still my problem has not been resolved. It has been two years and still nothing is happening. My contract ended in November 2014, I have been requesting to terminate my contract since then. I am still paying R200 a month for a contract that expired in NOvember. I over paid my account and was given a refund of R1800 in 2014 by MTN. I want to upgrade but I am blocked on the system, I went to MTN branch in Vanderbijlpark since last year April I have been blocked till now. I am still paying on a monthly basis sent proof of payment to the branch but still. I received calls and sms's that I am eligible for an upgrade, how is the possible if my account has been blocked by legal. I still over paying this account. Please just close it I want nothing to do with MTN anymore I don't even want to upgrade anymore I will find another service provide. Please just terminate my contract ASAP I am sick of this. Two years still nothing has been done, even when you call that legal department you hold for hours and never get through. I have been over paying I also want my refund back! Your systems are not being updated!