ACCOUNT HANDED OVER WHEN IT WAS PAID UP!

I purchased a contract on 02/11/2010 from MTN. I had the contract untill it expired and then transferred the number to prepaid. Now I am receiving SMS calls from MBD Attorneys, saying this account has been handed over, and that I have been put on ITC!!! MTN personally transferred this number from CONTRACT to PREPAID, and they wouldnt have done it unless the contract was paid up to date!!! I have asked MBD Attorneys to give me proof any documentation about this, and they couldnt. I contacted them last week, saying the balance is R552.00 that I needed to pay, and when I contacted them today, the amount was already R650!!! I tried to contact MTN myself, but they were on strike. I went to the MTN shop in our town, and they said, there is no balance outstanding according to their records. Now I am on ITC for NOTHING and NOW ANSWERS can be given to ME! This is ABSOLUTE NONSENSE!!! And by the way, MBD attorneys use the same reply for every comment that has been logged on HELOPETER!!!