No help - extremely bad customer service

Ackermans has sent me a very rude SMS, telling me that I have not made payment on my account. I have a stop order set up on my bank account, and the payments are made automatically every month. So without asking me they just state "You have not made payment, pay R *** on your account" Like really, where is the communication. Now I'm trying to get hold of them to resolve the issue. The WhatsApp number gets disconnected because their agent does not reply within the timeframe. My emails with POP's are ignored, and the only answer they can give me is my account is in arrears, even when I provide the Proof of payments. This is ridiculous.