I used to support this site, but over the last year they have had constant issues with stock and sizing guides being wrong.
Last November, they sent me a shirt that was completely too small and made me jump through a bunch of hoops before they would even allow me to return it! They admitted no wrong doing, even though I ordered four other shirts of the same style and sizing guide, and they all fit fine.
This morning, I tried to buy a shirt from them during their Nickelodeon sale, and had it in my cart, but it would not process.
They then basically send me an email blaming me for the issue as their site sucks and can't handle demand.
I would avoid these guys as they are untrustworthy and can't handle their own growth.