Help me resolve an issue

So I had a guy commission a costume from me, I quoted him, he paid me my 50% deposit. I kept up communication with him, until, I was done with the costume. I sent him numerous photos of the costume completed and asked for the other half of the payment. 

That was on the first of the month. Since then I have sent 2 emails telling him I haven’t received payment, or any communication.  I wanted to make sure he got his costume before the event he was going to… I have yet to hear from him. 

Thankfully the 50% down payment covers fabric cost. So I am just out my time in making it. I was thinking of emailing him for a 3rd time, but at what point does it become useless?  Any ideas?