Helpless I don’t know what to do

I had a contract with MTN that I never used in July 2022 because of the network coverage it never worked called them they tried to locate my house never worked, in October 2022 went the ***** branch to cancel they said can’t help me on things did online but I filled some form and they said they will get back at me the past 2 days been trying to get help coz it now appears on my credit report that I owe them they can help they say they don’t see anything on their system 🥵