How to change back my name in game?

I'm playing Battlefield 3.

My game name used to be Zioma_Zukerman. Now it's ziomazukerman.

I have contacted technical support lately, maybe this is the reason, maybe they changed something.

I want to change my ingame name back (nickname, nick name, game name, etc.). And I just can't find this setting in Battlelog.

And I can't find anything in web neither on this website about changing nickname.

Could someone help with that?

I just don't understand why did they put identifier as a nickname (or nickname as identifier). Whos briliant idea is that? Let they use avatar as identifier, this idea is just as good as previous one.
Unique identifier is an e-mail! It's unique, it's used to enter the account, what else do they want?!

And there is no place in battlelog profile editing where you can change the name.

EA is horrible, but It's just getting worser and worser, they are just breaking everything that used to work normaly.