I cancelled my contract with Telkom more than 18 months ago to sign up with a fiber option with another company

I cancelled my contract with Telkom more than 18 months ago to sign up with a fiber option with another company. I then started getting letters from collectors stating that I still owed more than R 3000 as I gave premature notice and my contract had not yet expired. I tried contacting Telkom and was sent from pillar to post. Not to want to affect my credit rating and being at the end of my patients, I paid the amount. This was more than a year ago. Now I am receiving the same SMSs stating the following : Telkom Reminder: Our records indicate a/c no *** is in arrears with R3399.61. Please arrange immediate payment to avoid suspension. The service has been *inactive* for more 2 years and I still cant get through to someone who can assist.