TERRIBLE service

I am really fed up with their poor service and I am on the brink of closing all my accounts with them to move to a different bank. I have been trying to sort out an issue with them since MONDAY, NO FEEDBACK to date. I was on the phone on Monday for MORE than 50 minutes. I'm getting threads because you believe there was a payment due on my credit card which there is NOT because a payment was made on the 2nd of March. There has been a mix up from YOUR side but I am the one getting punished so please sort this out ASAP. All I literally have been doing for the past two months is fighting to sort our issues! This is UNACCEPTABLE!