I commissioned an artist named "Black Walker" (http://blackwalker80.deviantart.com) to draw a simple color pin-up of an original character of mine on late September 2009. He showed me the sketch first before I sent payment, which I admit I was skeptical at first, but took the chance anyway. After sending the payment, he replied that the "final sketch" would be sent to me the next day.
Two months went by, and there was no response from him. He posted a journal entry on his account of a so-called "Daily Report" with an unsorted status list of commissions he's supposed to be working on. Two more months went by, and yesterday I sent him an email asking him about his status. I have yet to hear a reply from him. Upon viewing his dA account, other users he owes commissions to have expressed their complaint, also having no response from him.
UPDATE: I finally received a reply from "Black Walker" this morning with the finished commission attached. Therefore, the issue has been resolved. He claimed that his internet was down over the last couple of months. He also apologized for the long delay.
Thanks to everyone here for your input, understanding and support. :)