Dispute with Mobilesplus

I had a cell contract with MTN that was due for upgrade I did not upgrade as I was happy on a month to month contract at a cost of R199 per month On the 28th Jan 2021 I received a call from a lady who mentioned that she was calling from MTN and she had a good contract on offer which was better than the one I had. I mentioned to her that I am a pensioner and I dont need extra expenses in my life The lady was very convincing and promised me a cheaper contract than I had On her promise I accepted the contract To my shock my first bill was R982-16 I went immediately to MTN to cancel To my dismay I learnt that this contract wasnt from MTN but a call cntre viz Mobilesplus I tried cancelling it but i got no joy and I paid a total of R3694 instead of R1832 The breakdown is a follows March R982 April R1182 May R933 June R597 My normal bill was R458 a month I will gladly appreciate if you can assist me with the above MTN refuse to cancel but tbey are the ones who are receiving the payments Thank You