Procedure for item not received and no contact?

[bradlieus]

Just checking what the procedure is for this - I did a trade on August 25th, sent my card off straight away and still haven't received theirs.
Tried contacting by pm and trade thread, no response.
Luckily it's only a $20ish card, but what is a reasonable time to wait, and what do I do?

 

[motiv8dan]

PM a mod with the thread for the deal