Refund of ********** transaction needed

My younger sister had a ********** transaction that was made on her account about a month ago of R900 and something. She then went to the nearest branch to complain about it they said to give them 7 days to investigate while she asks for her money back from the said **********. 7 days later neither the bank nor the ********** have anything positive to say the bank then says they will freeze the transaction that the ********** made and then give my younger sister her money back by Friday which was two weeks ago and nothing has been done yet. She has an incident number that she was given . Please assist and send back the money as she needs it to pay for her school fees. It is not fair to be given such a run around when the perpetrators are committing such ***** on our accounts with money that we need.