»I can't register with my premium account

Hello guildcraft network my name is Exannger I'm new on this server and I'm a premium user so i bought minecraft premium since 4 months ago but i like play mostly in minecraft no premium servers.
Before i was no premium but and I wanted minecraft premium to play with my unique username and skin in every server because when i was no premium user i had to change username and skin always when it was already taken but now when I'm premium has happened the same -_- I don't know who's using my account he registered before than me using my premium username.
I'm saying the truth you can find me with this username in many social networks and games also here an screenshot in my mojang account.

I demand the account password need to be changed by a staff member (admins/mods) telling that person the why if he ask later and any staff member send me the password in private here using imbox, otherwise delete the account and tell me when to enter to can /register

Thanks.
Hope you can help me.

 

@Elphios

 

Since this is a cracked server someone could've registered your username first. You are free to download a cracked launcher and play here with a different username.