OK so I bought a brand new sealed BB Tour off ebay from a reasonably reputable seller, 20 feedbacks. Anyway, couldn't active the phone. The chat representative said the ESN is linked to another account. i said the phone is brand new, and he said that anytime someone buys a phone, it is linked to their account.
I have Sprint, and when I tried to activate my brand new from Sprint Tour, they told me the same thing, apparently the ***** I was talking to had no clue what he was talking about because the second person had no problems....
Basically I bet what happened here is the seller used his NE2 upgrade to get a BBerry Tour and then tossed it on eBay without activating it first. If he activated the Tour then switched his account back to his regular phone you might have better luck.
I pulled a trick similar to this with my mom's phone (a family share line on my account) and the new phone I got her that was meant for me wouldn't activate for my number until AFTER I first activated it for her number.