Discovery Just Does Not Care About It's Clients

I have two accounts with Discovery Bank, a transaction account and a credit card account. I have faithfully made payments into the credit card every month since I have had the credit card, and even settled the full amount owing on at least 3 occasions in the last year. I was aware that I was over the limit by around R1 600 but was planning to pay that in with my payment on the 26th as I do every month. As usual I am always short of money a few days before payday so my partner deposited R1 000 into my transaction account this morning, I was on my way to go put some petrol in my car and go get some groceries and I got a notification from Discovery to say that they used the R1000 in my transaction account to set off the amount that was over the limit in the credit card account. I called them, they were not interested that they had taken the last of my money that was meant to feed my children, put petrol in my car etc. They say that a notification was sent out to make me aware that they would be doing this, when in fact all their notification said was that the account was overdrawn and to make payment to avoid penalties or locks on my credit facility - nothing about the fact that my account will be debited on 23 October. My partner then put in a further R700 which they then proceeded to take out my account as well. I am now left with R0.00 in my bank account, I have no money for petrol and no money for groceries. Discovery Bank has not acted in good faith and has put me in a very precarious financial position - they just could not wait until the 26th when I would have paid whatever was owing on the account. They do not care and went as far as to say that they were doing it to help me!! It is a term of their credit agreement that they can set off amounts from one account to the other but please.....do this with a bit of consideration?? I will be moving my transaction account to another bank and will pay off this credit card in full in the next few weeks and this will be the end of my relationship with Discovery - banking and medical aid.