Incorrect contracts under my profile

I have been having a contract with MTN since 2010 and been very loyal to them.Last year early I misplaced my phone and was told it won't be paid out it's not insured,how so I don't know as all these years I would make sure my phones are insured...the claim wasn't handle accordingly and not fairly.

This year I'm experiencing bad service once again with them as the contract I had expired in Feb if not mistaken,and I kept getting calls from agents saying they from MTN to upgrade it.I refused.1 afternoon I got a call same offering I refused and next thing I got an email that I have taken up a new upgrade contract with MTN .I emailed complaint to dispute this and tried to call the customer care and they didn't assist.

April I decided to take up a new data contract with MTN after I was called as well by agents offering a DATA SIM PACKAGE deal .I accepted that one .I was paying accordingly.i was told I can upgrade anytime. On the 7th of June 2023 I upgraded my contract to a phone deal where I was told I will pay R435pm and for the 1st payment it would include pro rata and it will be R581 but they took a less amount. Last week I got an invoice that my next installment would be R1896.47. I went to a MTN store and I was told I have 2contracts that where upgraded before time which I totally despute.I only agree to the data SIM contract. Please assist me with this issue as I totally understand and don't agree to all this .