Fnb stopped our homeloan flexi account and claim the reason therefore is no funds in my account

I transferred money into my debit account the evening when the debit order went off. We receIved messages that the debit order went of and the following morning we receIved that it failed. I phoned them over the weekend and tried to resolve the issue: It is not that I did not have the money. They said I have to phone the Monday. We phoned the Monday and the debit order went of on the Monday but they took away our flexi account because it did not go off like they wanted. We phoned them and said the money was in the account because it was transferred from on account to another and they said they would make an investigation. The one person call us and tell is this how it is then another person tells something else. I never saw a company that is so confused within them self. I would like from Fnb what will happen now because I am really considering it to go to another bank. They do not even let you know anything. Then they phone you and try to Market stuff to you. If I year it is on behalf of FNB it just press the phone off. Thanks "FNB HOW CAN WE S@%W YOU"