I bought a blackberry 8100 off of ebay (

) and it was on the Cingular network. I'm on the Rogers network.
My problem is that I can't set up my e-mail on my pearl. It keeps saying that there's already an account associated with the phone.
I've called Rogers and they said that I need to contact the previous owner and get them to call AT&T/ Cingular and get them to "release the PIN". I've contacted the ebay "store" that I bought the phone from but they haven't responded back.
What should I do next? Any ideas? Can I do something else to get my e-mail to work?
PLEASE HELP!!!