Deduction from another account without permission

I have been awaiting my cards from a separate bank for a while now. Because I cannot withdraw money from my own account my boyfriend suggested I ask my boss to pay the money into his cheque account. He has a loan with Standard bank bank both accounts are with them as well. On Saturday morning they phoned him and asked if they could withdraw the amount for his loan from his cheque account and he instructed them not to.

Today which is Monday they withdrew the money even though he has told them it wasn't his money and essentially have now ****** my money.

How can I rectify this?