etsy folks...

I've made several purchases from etsy (obviously). How long should I wait before I report a non-delivery with them and list a negative comment/feedback for the seller? I purchased an item a week ago and haven't heard from the seller. I've tried to contact this person, but I'm not getting a response back. (I've convo'd twice and e-mailed once.) It wasn't until after I ordered that I realized this seller doesn't have a selling history. Believe me, I never would have ordered if I had figured that out earlier. *sigh* There is no change in history from "payment received" and I've received two other items that I ordered from different sellers on the same day.