We are companies ***gy banks

Is anyone else being debited whenever Discovery feel like it on their credit cards? I have a discovery credit card through FNB, now through Discovery as they bought their book from them, however this month they have debited R1700 without my consent or knowledge, they tell me it was a mistake? A mistake made by a multi million Rand company that I must now sit and suffer for and not be able to provide for my young son because they have take most of the little money I earn, especially now during COVID, I'm disgusted and embarrassed for you, but I'm sure Discovery wont even care.