Fnb stole my money, no one is helping

On Friday the 30th I had to deposit my child school fee, I went to Midrant Carlsward ATM Branch. After putting all the information required I then inserted R3500 and the machine counted and return back R100 note. I then reinsert it and the machine counted and never proceeded to the next step. It then gave me slip saying transaction was not successful but did not return my R3500 back but instead it returned the FNB black card. I took the slip and the card gave them to FNB employee who then took the card and put it back to the machine. He then referred me inside where a ticket was opened. Even today I am still waiting for the branch to assist me and my child is still not at school.