Unhappy customer

I just app**** for my home load with FNB and apparently i am blacklisted because i owe vodacom R1052.93. Mind you i have not used vodacom since 2015, i have been with MTN even since. I remember calling them to cancel my then contract but no paper work was ever sent to me.I asked for the breakdown of this cost from VVM their legal company and they could not send me the details. If my previous account with vodacom was a contract, how would i only be owing them R1k since 2015. i was forced to pay this amount by VVM yesterday and I did. I do not owe Vodacom this month and my name should not be blacklisted.