Telkom hustling for payment, but no payment is due, and no installation.

I cancelled all my accounts, well actually you couldnt install my fibre after 3 months and told me you cancelled it. My account is in the positive, and I keep getting debt collector threats, and today someone phoned me up from telkom, only to tell me that their system is offline. I have phoned and emailed and they keep telling me its been sorted out only to get harrassed again about payment notices. Please contact me and let's sort this out once and for all.