1. you shouldn't use the mcleak authenticator, it gives stolen accounts. 2. just install the linux version (it comes in a .jar which works on windows and mac too)
I think someone stole your MC account, you can't take it back without waiting for mojang to give it back to you, unless you still have a tab on your browser what still has you mojang account open, which is unlikely.
If you want, I could give you one of my accounts until you problem is solved.