FNB not display any spirit of Ubuntu to their customers

I'm very disappointed and under a lot of stress caused my FNB. I had a loan with Fnb and was retrenched from the job where I was earning a good salary and in January 2021 I called FNB to notify them that I found a 6 months contract job however the salary is way less but I would like still like to pay my loan at a reduced installments. I was advised to send proof of the new salary and ID copies to special arrangements of which I did. I even made an arrangement to pay off the arrears amount in installments over 6 months. I kept calling to find if theres any feedback for me but was told not yet but the team leader for special arrangements Sarah Trullip is working on the account and I will receive feedback with 48hrs. To my surprise that was not done, my salary came in and FNB debited the full loan amount including the arrangement that I made to may off the arrears amount after I have explained that my salary now is no longer the same. They took over 90% of my current salary and now now one is able to help or reverse the amount and now I'm stranded because I still have to travel to my new work, still need to pay rent where I'm staying and pay for other things. How can FNB become so heartless after I have been with them for so long and my accounts where always up to date with them and even now I was the one who informed them that I'm working now and would like to pay a reduced installment. How can they deduct more than 90% of my salary and left me with almost nothing? How do they expect me to survive the whole month? Do they even care about the stress and depression they are currently causing or they just want to debit their money? I'm so dissapoited stranded don't even know what do do any more. Do I need to change my salary bank maybe so it's no longer paid in to an FNB account because it means now every month they gonna be deducting my whole salary without caring if I'm left with anything or not. I need someone to please attend to this and reverse money because I still have other responsibilities but they just wanted to take everything from themselves. This is really disheartening and not good at all, clearly FNB is not displaying their Ubuntu values and how can we help you because instead they are making my life more miserable than it was before.