Invoicing confusion and poor service

I've only been a client for three months now. I paid June with the Installation and activation fee end of June. I received an email where they said my account will be debited mid July for July and then only end of August for August. At the end of July they debited my account. I phoned them and the lady said I can reverse the payment and they will debit end of August as per original mail. Now they keep sending me emails saying my August invoice is outstanding. (After their email confirming this and a phone call confirming this)

Doesn't seem like their accounts department know what they are doing.

Very very very unhappy with their service and seriously considering moving.