Very unhappy account holder

I payed my account in full on the 01.09.2020 and requested that the account to be closed. On the 13th I received a message 01:30 am that I have an outstanding amount on my account that needs to be paid. I phone just to be informed that the account is still active. They were supposed to phone me back regarding this but till today im still waiting. Phoned again today, twice as the 1st agent just put the phone down in my ear, just to hear that NOTHING has been done regarding my account and that i have to pay the amount that is outstanding. It will take the supervisor 7 working day to concact me back, really it takes that long. I wonder how many customers have to go through the same thing. How many people need to lose money because Edgars employ people who clearly don't know how to do the job.