Unauthorised/Not informed of decrease on overdraft - last monies in account gone.

After much deliberation we decided to apply for Debt Review as we struggled to make ends meat and pay accounts. NDA (National Debt advisors) requested all debt from FNB direct and only received my credit card and revolving credit debt from the bank. They didnt send anything regarding my overdraft to NDA. 9Days after debt being registered with NDA, FNB decided without notifying me to decrease my overdraft limit with R2000. I had my last R1000 in my account to get us through the month taken. My private banker confirmed they did it because of Debt review. I tried phoning FNB and after being transfered roundabout 6-7 times, nobody could give me any answers regarding my enquiry. After the last transfer my last R150 airtime got depleted. With no money in my account, I couldnt even top-up to phone back and get clarity. To take my last bit of money in a already stressfull time and not even discussing it or make prior arrangements with me, is not good practise in my opinion.