Worst service from Standard Bank Credit department

Following a previous post on Hello Peter, I again have trouble with the same loan account at Standard Bank. I have previously struggled for 4 months to get money back from Standard Bank which just vanished from my account. I opened a revolving credit plan for which Standard Bank has set up a debit order that goes from my savings account each month. On a previous occasion they have deducted the debit order twice, but only one amount showed in the loan account, the other was just missing. After eventually getting the money back into my savings account (after posting it on Hello Peter), I kept getting notices to say that my account was now handed over to the legal department as I now “skipped payments”! When phoning the credit department, the consultant was unhelpful and said that I must ensure I have enough money for the debit order to go off. It took a while to sort out that I did NOT owe any money. A month ago I got a new cellphone number which I updated at the bank (took 3 tries to get that right to be able to receive notices again). After that I keep getting phone calls from Standard Bank Credit department. The first call I answered they started talking about my loan account, so I told them I will lodge more complaints because this was sorted out that I do not owe money. Then the lady said, no, they saw I paid extra money to the account, so they want to know when I will pay the rest of the loan off so they can give me a discount. When I said that has got nothing to do with them as my debit order still goes off monthly, she said they will keep phoning until I tell them. And they do. A week ago, immediately after that phone call, I went to my local bank to query this. They told me my loan account is up to date and it does not sound like a legit phone call. But I keep getting calls and even sms’ saying my account is at the legal department. Today I got an sms saying that because I have not responded to previous correspondence my account will be handed over for legal action. I feel like just closing all my accounts with Standard Bank.