Taxfiy Driver is a louse ***** and ****!!!!

I took a Taxify from 66 Main Street in Rosettenville/Townsview to Fraser Street in Turffontein which I always do only this time I actually forgot my phone in the Drivers car his name is Astonish and his contact number is ********** he drives an Toyota Etios so immediately after he left I realised that I actually forgot my phone is in his car so naturally I called my number repeatedly several times and it only rang and rang endlessly he did not answer my number at all, I then tried to call the Taxify offices number which just rang and rang as well without any answer as it was a sunday I did think no one is working on sundays so I also used my brothers app to contact them and inform them. So this morning I get to work and I email them all they respond they gave me the drivers name and number so I called Astonish guess what bull**** story he tells me? No he did not find or see any phone when I know for sure I actually forgot it on his front seat he did have a trip a short while after me maybe that passanger took my phone? Am I going to get my phone back even I pleaded with the head office and I am not going to stop is there anyone that can give me advice on what I could do? I am not rich I cannot just afford to go and buy a new phone I need help please the driver does not want to return my phone I know he has it for sure? The head office is trying to assist but is also useless to be honest I need my phone back it is all I want?