You waited patiently for him to "get back" from where ever. If he is legit, he should do as you requested. But I'm skeptical of someone who posts such an expensive item knowing they will be out of town when the time expires; a $5 - $10 item sure, but not a whole bike.

I hate the pre-printed labels from USPS that allow people to meet the shipping time limits of eBay without in fact doing so. I've had more than a few cases where people print them out, it shows the item has "shipped", yet it doesn't get to the PO for a week or more.