Are you pushing the button all the way down or just to the first click? Mine currently works when pushing all the way down but not to the first click. I'm sure you've tried this. If it fails to work at all, you might need it serviced but I don't know for sure. The camera button is the weakest button on the whole phone in my opinion. It's way too soft.
The only thing I did was rooted my phone I thought everything had gone perfectly but after trying to use the camera but I realize it's no longer worked