Bad service and overbilling

First spoke to accounts and support about moving fibre from one address to another as new one already had installation and they said there wouldnt be any charges. Did exactly as they said and after four days of countless calls my fibre was finally working. Then i get an invoice for a new line, phoned accounts and sent email as per thier request so the account could be credited. Now my account has been debited for a new line, so now paid for two fibre lines this month. I am changing isp's at the end of this month as afrihost is a nightmare to deal with.