TELKOM and FINRITE are *******

In June or July I was offered an upgrade but I declined because I was happy with my current phone, so I called to ask how to cancel my contract and insurance once my contract ended. I was told to log onto the portal which I did and created a ticket to cancel a few weeks later I got called to confirm my cancellation and we agreed. My contract was cancelled and converted to prepaid yet I'm still being billed for insurance. So I called and was told I need to contact Finrite which I did and twice they ignore my emails. then I get an invoice to say Im owing a huge amount because I didn't have enough funds in my account(reason being I DID NOT know I had to still pay for insurance) plus there's a penalty fee for your mess!!! I logged two tickets recently demanding this to be sorted out yet again my requests get ignored by both TELKOM and FINRITE