Unauthorized debit order

I'm a loyal customer of capitec Bank for years but I must say I'm really disappointed by this bank. Had taken an access facility with them and I was unable to pay for I was on maternity leave and I got half of my salary and I was depending on uif which is still giving me a problem even now... I made arrangements to pay R300 on my access facility in December 2021and that they can start debiting their full amount on the 25th February 2022 because then I'll have January to pay for my other debts but to my surprise they debited twice an amount of R5600 which I was supposed to use for my rent and food, when I called the customer care I was assisted by this rude lady just forgot her name and she told me she can't refund my whole amount but R2000 only when I asked why she told me I can't skip the month of January but I explained about the arrangement she told me she sees no arrangements and she can't help me and indeed she refunded only R2000... Capitec I loved your bank but you left me frustrated and angry really I'm highly disappointed please help refund my money back