Poor debt collector outsourced by Telkom!!!

I paid my Telkom account through their third party on the 30th of June 2022. My actual amount was R1718.64 but I was charged R2518.64 with a difference of R800 more. I have been requesting a paid letter as a result of my Telkom account not yet being settled with Telkom. I have proof of WhatsApp with them, and proof of payment.