Terrible customer care and service from Telkom

Terrible customer service from Telkom. I have been faithfully paying my Telkom monthly bill on time. Until on December when I tried to pay on the app and the payment wouldn’t go through. I went to a Telkom store to request for help and I was given a code to scan and the payment didn’t go through. I ended paying from the website using a scan code and the payment went through on the 21st of December (R269). My due date for making payment is on the 31st of each month. I felt relieved thinking at least the payment was a success. To my surprise, today on the 6th of January. I received an invoice saying I’m owing R471 because of an unsuccessful debit order. How come my payment does not reflect but, you took money from my account. You’re basically penalising me for a payment that is not reflecting when I paid 10 days before the due date. I have been trying to call you the whole day and nobody is answering my calls. You have such a terrible customer service. In other ways you wanted me to pay twice for this month of December.