I had my number change by verizon back in March 2013. Afterwards my online message center verizon call assistant old phone number still appears and is inactive. I've called so many times to technicians to correct the problem and each call was transfer or escalated and till this day I can't use my Verizon Call Assistant to see who called me, check voicemail. I had this feature on my old number. Wouldn't Verizon know how to correct a visible problem?
Welcome to the forum, this thread may be of some help: http://forums.verizon.com/t5/Home-Phone-Landline-or-Digital/Verizon-Call-Assistant-No-Longer-Availab...
call assistant doesn't interface in the verizon portal. it's a seperate webpage and works for me to this day.
it doesn't automatically transfer to new locations though, so you have to sign up at the new location, and register online, it should use the new user id and pw that accesses your current bill.