********** contract extension

My contract is due to expire in February and when I called MTN on Dcember 6th 2017 to inform them of my intention to cancel the contract, MTN informed me that my contract had been renewed with CellCom in KZN / Newcastle on 18th November 2017. I was in India at the time so there is no way I could have extended a contract I am wanting to cancel. MTN told me there is nothing they can do as their 3rd party is the one the extended my contract and I have to handle it with that company. I mean what kind of service is this? MTN provided these people with my details and now I have to sort it out?? I have never even been to this Newcastle place and now I am expected to run around to sort this out. These are all my references from MTN: ********** 008 (6 December 2017) ********** 86 (28 December 2017) , I have indicated to MTN that I do not use that SIM card and I even went to a store to have it blocked indefinitely. I have yet to receive any communication from them, I am at a loss as to what I should do and what recourse I have. MTN fix this