No words can describe

I have a standard bank home loan and had a missed debit in the month of May 2022. 2 different agents from Standard bank home loans collections contacted me and I eventually made an arrangement for a double debit to go off in the month of July. In the month of June another agent called me with regards to that same missed debit order and I explained that I made arrangements for July. My debit order in the month of June went off successfully so I only owed May instalments. In the month of July I left the amount that Needed to be debited in my account for the double debit to go off but standard bank debited that double debit as well as another debit so all in all they expected me to pay 3 instalments instead of the double debit that I was actually supposed to pay. Now because of that my credit scores went down and I asked so many agents to get a manager to call me but instead no manager called me. I got an email saying they tried calling me but I didn’t get a missed call or anything that I no of and then a different agent calls each time for the missed debit. I need to get my home loan up to date and in order to do that I need someone higher than an agent to call. So I’m not sure if standard bank home loans even cares about there clients but so far it shows that they don’t and all they care about is taking the instalment. Because today I got a call from a standard bank agent again about that missed debit order but still no manager and the call cut after I asked the agent to hold on for me but she did not call back after it cut which means I will be getting a different agent again to call me and then I must re explain the situation again and again and still won’t get a manager to call me to help me. If the second missed debit order was my fault then I would take responsibility but this specific missed debit was not my fault and now they want me to pay the updated instalment and not the amount that was missed which I also feel is unfair.