Credit card — CITIBANK, N.A. (WV)

Problem during payment process. I forgot to update my payment bank account. with Citi Bank. So when I made a payment of around {$3500.00} my old bank sent me an NSF notice. I emediately called Citi, explained what I had done and tried to change my payment to my new bank.They refused and charged my cc for payment not going through. Then they ran it a second time with the same outcome and extra charges to both accounts. Then I called Citi again, the girl said she cancelled my auto pay and deleted my old bank info. Then I made a one time payment of {$4000.00} using my new bank on XX/XX/year>. On XX/XX/year>XXXX Citi attempted the first payment a third time, same outcome, same charges to both accounts. How Can This Be Legal?!!! I won't cancel my XXXX XXXX credit limit card, that will jus