Cancelled Contract

I took out a cellphone contract online with MTN in September 2021, a day after taking it up i called to cancel the deal because there were things I was unclear about and the phone was never delivered. I recently found out that I am owing them and it’s affecting my credit score, I went to a branch in middelburg mall i was told that they cannot assist, I called the number they gave me its not going through. Please remove this from my name