Disappointed

Since contract started debit order payment has been done. Jan 2023 and Feb 2023 paid, end of Mar 2023 I get a call from the debt collector informing me I owe R209 because I never paid for Jan 2023 I phoned Telkom and sent my bank statement proving I made the payments and the consultant informs me they can only pick up one payment and that's why I am in arrears. Consultant review my email and acknowledge that 2 payments are visible on the statement accordingly. How is this fair? Telkom never phoned me to confirm anything before placing me with debt collectors and I did make the payments. My credit score and Name is now affected because of this, I guess the only thing they care about are sales numbers because when I asked the guy who helped sign my contract up about this he told me his on leave didn't even refer me to any1.. Truly disappointed, I wish I never told my family and friends about how Great Telkom was..