Money transfer theft

My sister went to do a money transfer at your Gateway Mall store in Durban North and when I tried taking the money out it was already withdrawn from an Absa ATM in Joburg at Daveyton mind you we are all in Durban. I called them and they said my sister needs to come back to the store of which she did. All they said to her was, this is not the first time they have someone complaining about this and their system is hacked by people who ***** these withdrawal digits and the only thing we can do is to open a case. I really smell a rat here, how did they know the withdrawal pin. I really need my money asseblief.