Oh Sky!
I only pass along things that I see, hear or read in hopes that it will stop someone from trying to wiz snipe, etc. and lose their account. And then usually only after I've thrown a pillow across the room and have a chance to calm down. This whole thing just makes me so upset and angry to see these people with nothing better to do with their time than try to steal from others.
Band, have you been to any usershops, especially those with very cheap items, like codestones? If you have and you got a blank page or the shop didn't have the item but it still shows up on the shop wiz, then there's a good chance you were cookie grabbed.
As far as I know there is no way for this to happen via neomail. If that were possible, just about all of use would have lost an account by now.
The best thing for you to do is, if you've already filled out the form, is to wait for TNT to contact you. I am sorry that you were yet another victim.
The only thing I can think of to try to protect ourselves is - use the PIN that TNT has provided for us, and use that everywhere possible. Don't go to usershops, especially ones with items priced "Too good to be true", stay away from userlookups or just about anywhere a user can edit a page. When you log out of Neo or anywhere, clear everything. Don't go to any off-site links anyone on Neo may give you.
Finally, if you must shop, etc. and use windows - open Notepad and write a list of long, combination Upper and lower case letters and numbers - save that. Have your user pref page open in another window or tab; have your current password in the space provided. Copy one of the passwords on your notepad and quickly paste that into the 2 spaces provided and change that password. Make a note in the notepad of which password you're using.