Unauthorized debit order / Super delay to refund

I have a Personal Loan with FNB, I fell into arrears because I was out of work for a few months. Bare in mind, there is a debt collection agency that they use to collect money if you in arrears. I finally got a job but needed to relocate to CPT from JHB. I just recently moved into my own place after two months but made arragements with the LandLord to pay the deposit half and half together with the first month rental. Now end of Jan when the second half of deposit and rental is due I cannot pay it because FNB WITHOUT authorization, instruction, communication or notification deduct R20K from my salary. NOW, this means I have no money to pay the rental and deposit, no transport money, no food. I contact the debt collection agency and they shocked that FNB went to lengths of this deed without even them knowing. This was done on the 25th of Jan 2018, so they said they will spare me the grace of 50% refund AND keep the rest even though I should be supposed to pay R1350 monthly but i made an arragement of R3000 to cover the arrears and trying to do the right thing. It is the 8th of February 2018 and I still do not have the refund in my account. I have been calling everyday since and the agents just brush me off and say that it should be in tomorrow. All my debit order bounced and guess what?? my account is in the negative and WHO IS CHARGING ME FOR THIS..you guessed it, this trash bank FNB!!! So now I have been handed over to TPN with a letter of demand for the amount owing and STILL NO REFUND. Now tell me, HOW DO I LIVE? I have been with FNB for almost 20 years but they ***** ME OVER like this...and now i am trying to hustle odds and ends to try get to work and eat every day. I HATE FNB, they don't care about the people that have been loyal to them!!