R40 000 ****** from my Nedbank pocket savings, bank claim they dont know what happened to it.

R40 000 disappeared from my Nedbamk pocket savings on the 30th of Nov and the bank says they dont know what happen to it. I called the bank the next day they said they have an IT problem, I should call on Monday. When I called on Monday they tell me I should call Wednesdays they still resolving the issue. On Wednesday they say they dont have a lead time I shoud open a case with complains department. I got a reference from complains department, today is 30 days later and they still say they cannot refund my money they still investigating. I need to pay school fees and buy uniform. I don't know what steps to take next.