*****ing my life and making my credit bad

I had a fixed line with them more than 5 years ago - I called to cancel the line they never logged the call or whatever and it was not cancelled so the outstanding amount kept coming up and growing on my ITC. last year after giving up trying to sort this out I decided just to pay the amount to get it off my ITC. I payed in full on June 2022. I have been to 3 stores sent emails and tried to call and cannot get anyone to assist me in removing this from my name. I lost my home loan over this and my cell phone company will also not upgrade me now.