Robbing customers!

I paid my account via EFT from pep website ozow on the 30th of June. I keep getting messages that I didn't pay, I sent proof of payment on the 11th of July for the 3rd time to show when I paid the account and the time. I was on WhatsApp chat, and they said they are useless; they take too long to reply and once you don't reply in one minute, they end the chat. I have been calling the contact centre with no success I am being sent from pillar to post. They acknowledge that they have a problem but don't know how to resolve it or how long it will take. This is ridiculous service to say the least. You do not care about customers and their credit scores. Why would you offer a payment option that doesn't work for your company? Poor service I'm disappointed and I think paying up at the store and closing the account will do.