Character's Names Changed after hiatus

Hello I just recently took a hiatus from the game as I was moving in with my fiancé. I selected Icecrown where it said I had 8 toons on that server only to see two there in character selection. I don't mind the lost toons they were all lowbies but I'd like to know if I can get a free change for the two toon names that were changed? I don't think I had an inappropriate toon name but both my level 58 shadow priest and my level 60 mage's names are changed to C_(Random numbers.) I really wouldn't want to take money out of my pocket to get a name change for both of them but if I'm not allowed a free name change I'll just have to deal with my new odd toon names and be referred to as "C" for now on lol.

You will be asked to give them a name the first time you log in. You will be able to use their previous names if they are still available.