No reversal

My mom made a payment R1500 to a wrong cell phone number , she went to the branch and she was told the money is in that person account , but they cant reverse it , and logged a call for her , she went to follow up then they said they person is not picking up the phone , so they cant help ,

Kindly assist , because I don't understand if that person will never answer their phone then what ?and most people they don't answer the calls to the numbers they don't know , we need those funds for the kids groceries .