Disappointing service

I have relocated from South Africa to Scotland and tried to cancel my cellphone contract with MTN. I had the contract for more than 2 years when in July 2022, I asked them to cancel it. They came back to me on email and said that they required my ID number which I then sent them. Unfortunately when I started the contract, I put it on bank debit. I now still get charged the standard charges, no usage, every month. I have tried many times via email to cancel with no success.