LOST PHONE IN STORE

On Sunday me & my wife were shopping at Ackermans, clearwater mall. When we to the car we realised that my wife forgot her phone in the fitting room so I ran back to go look for it. The shop was closed but the workers were still inside & I told one of the ladies that my wife forgot her phone in the fitting room and she asked someone to check. I called it and the line was busy, a few seconds later it went straight to voicemail. The lady said there's no phone there so I left. Later I used Google's location history to trace it &it showed that at 18:14 it was at Baragwanath taxi rank, soweto. I checked again later and it showed that the phone was in Moletsane, Soweto at 19:22. In the morning I went to the store to talk to the manager & she told me that it sounds like one of the staff members took it since most of them stay in soweto and they go to Baragwanath taxi rank from clearwater. She asked the staff who stays in Moletsane and found one person who stays there but they deny taking the phone. The location history shows the exact location of where the phone was last switched on. I would like to know what strps can be taken since I know the location of where it was last switched on.