Bad service affects me over a year later

I cancelled with 8-ta in 2013 because a new tower was put up in my area. I lost all signal at that point so couldn't use the service anymore. Technicians came to my home to try solve the problem but there was no resolution so I cancelled. I refused to pay for a service I didn't receive and wanted that balance written off. It wasn't and after reversing multiple unauthorised D.O.s with my bank I have now found when applying for new credit, that I have been blacklisted by Telkom. I'm furious. Please resolve ASAP.