Credit card payment date changed without my consent

Still the most innovative bank in SA Ene in the times of Covid 19. This time they changed my credit card payment date without my knowledge, now I'm receiving smses, emails etc telling me to make a payment. My payment date was the 25th and I have already made the payment. So today I'm told my payment date is the 31st and I should make a payment. This will mean 2nd payment in 1 month.