theft

on the 19/09/2015 I went to mc Donald's atterbury Pretoria for a kids birthday party, my phone was ****** in the store by one of the stuff members named Grace. a security video was shown to me on the 21/09/215 of her taking the phone from my table. i was told by the manager that the video is not clear and that she will get people to clean the video and I should come back on 25/09/2015,i then received a call from the manager that they could not clean the video and that there is nothing I they can do for me. what I fail to understand is that a crime was committed at their premises and me as a customer am the one suffer. i am utterly disappointed at how the situation is handled especially from a big known company as mc Donald's