MTN contract *****

I opened my contract 2008 last year 2024 I decided to cancel it. I went to nearest mtn they told to call the customer service. While I was still struggling to cancel I was receiving lots of calls the I must upgrade I told them I didn’t want to. When I checked my profile today on Experian my contract was upgraded with a different number. Which is not my number, I called MTN they told me the company that did upgrade on my behalf is EOS upgrade. How can someone take contract on my behalf without producing and verifying correct documentation. MTN failed me when we opening contracts they can help at the store, but when closing they don’t want to help.