Credit Card Unjustly Suspended

This is the second time that the Standard Bank Credit Card division took a payment from my Cheque account before the 25th of the month, which is the date that we agreed on per telephone conversation. My salary is paid on the 25th of each month, yet they try to take the payment on the 22nd, which is naturally returned because of no funds available. Then they phone me repeatedly, and very rudely demand to know WHY my credit card has not been paid. To worsen the situation, when I do try to transfer payment via internet banking, my credit card is not available. How am I supposed to make a payment then? The first time this happened, as previously mentioned, we agreed per telephone that I would make payment by the 25th of the month. Why do they then still try to take the money before that? I feel victimized as they are usually extremely rude and makes me feel like I am a ********, when I have no control over my account not being available for me to make payment. I have been a loyal customer of Standard Bank for almost 2 decades, and am supposed to be member of their prestige banking, yet I am not treated with respect.. I am very disgruntled, frustrated and extremely disappointed.