They take your money as they please

I wanted to buy food but my card was declined, I then checked my internet banking for info on whats going on I then saw that R500 has been taken out of my account with only journal as ref. Monday I went to ABSA to find out whats going on and they said that its for my credit card payment that Im behind on, when I told them I am paying R50 a month as that is all I can afford and after many times of trying to make an arrangement with ABSA for the R50 they kept on refusing as they say its not enough eventhough thats ALL I can afford so instead of not paying anything I payed the R50 December last year they took R300 I werent able to pay the last 2 months as unforeseen circumstanes came up and now they took R500!! That is my bread and food money what will we eat now? When I went to Absa today the lady that helped me couldnt answer any of my questions I asked her how can they just take money her reply was I dont know, she then stated that they werent able to get hold of me as they have the wrong nr but as I then told her how do I get notifications from my acc if theg dont have my nr, again the answer was I dont know, I then told her to just rather close my account and it wasnt done either