Where is my final bill?????

I canceled my Telkom DSL line on 3 March 2020. No phone calls as the email indicated and no final bill received up until this month. When I started the contract I had to put down a R700 deposit. Now I see that I have missed payments on a bill that I have not received. What happened to my deposit?? Surely you would use that to settle the final bill and if it was short send me an invoice for the outstanding amount. This has now gone onto my credit score and affecting me negatively. Since the email verification of the cancellation I have not heard a thing from Telkom. I find this quiet pathetic from Telkom side. It in now mid November * months later. SHOCKING!!!!