Have you done a battery pull, or tried going to your carriers bis login page from your pc and sending you service books. Also are you sure that he put a blackberry data plan, i work for att and that happens alot. SOmeone will add a data plan or media net plan not a blackberry data plan
i did the battery pull, im going to try the bis page even tho i dont know what that is, then im going to call verizon, i just hate them, id rather be on here.
search google for verizon bis login and sign up if you havent already if you have just log in. and on the left side of the page yu should see something that says resend service books.
Any chance of contacting the old user? You are going to need to get their pin released. If not try contacting your carrier to see if they are able to assist
This happened to my next door neighbor lol. whenever she has a problem with her bb she comes to me. YOu can call your carrier and what they can do is actually change the email address registered to the phone and reset it for you or do a pin release which will clear things up for you.