apparent outstanding amount = trauma

I have had laywers repeatedly tell me I owe MTN money starting back from 2016/05/17 first from MUNNIK BASSON DAGAMA INC. Then from NORTON-LAMBRIANOS (S.A.) INC a few months later

I have repeatedly told them I have cancelled it, but never filed them the cancellation papers...

I recently found those papers and sent it off to these lawyers... Just for MTN to come back and say I owe them for returned debit orders..

I requested how it is possible because I know from not just MTN but also Vodacom I couldn't possibly cancel the contract had I owed them money ... The other day I went into MTN and asked if I still owe 1000 rand and want to cancel my contract, how do I go about it, the rep**** by saying only once I paid the 1000 rand can I cancel. I called Telkom and Vodacom also to be sure of my situation ... I have the proof of cancellation for two contracts . I don't know where to go from here and believe they have blacklisted me in the whole situation

They sent me a statement showing I paid well all along then it just stopped... Whereby the lawyers told about many unpaid debits?

U see loads of transactions on this statement but not the amount I paid in cash the day I went to cancel this existing contracts...

I see all the complaints online from consumers and MTN.

MTN how do I resolve this? Is it possible to cancel a contract if I'm still outstanding?