I think it's definitely worth making that call ... I don't know about CardAvenger, but I'm sure there are many of us who do not intend to renew, who never sent in an invoice and never gave the cards any indication of any interest in renewing that they are holding out hope on (or at least holding the seats open a little longer due to the lockout, economy, etc)
If I can still get my same exact seats that means they either weren't filled due to no one wanting to relocate to them or they were not put up as an option as the organization was trying to entice me back with this later date ........ although not the greatest seats, i'm guessing it's the later and they would either have to open them up for a ST relocate or just put them on the single game market