Capitec Taking Advantage of clients

I lost my job in July 2021 and I made an arrangement with the bank that they can take R500 up until I get a job. So yesterday 27 January 2022 I received my UIF of R6225.22 and capitec decided to deduct R5731.61 and I was left with R491.18. This is my UIF money and I am unemployed at the moment and I have 2 kids who are both going to school. Why do we make an arrangement and then you decide to take money from my account? It's Uif money it's not a salary. I'm expected to buy groceries and survive on this money.I feel like capitec took advantage of me because I am using their bank account to receive funds. How do they expect me to survive if they take money out of my account when I am not working and we did not agree on that money.