Unable to cancel contract

I have been struggling to cancel a MTN contract from July 2024 without any luck, it is an old rooter that I used to use and haven't been using for years, I mailed the retention team in July 12024 and their response is that they cannot help without cell a number (which I don't have idea of what it is since I haven't used this in years) I referenced the reference going off my bank account plus my ID number and still they can't help. I called the Contact Centre but again with no success because I don't have the number in question...Can someone from MTN please make contact with me to resolve this. Werner Busch