So, i just bought FNV Ultimate Edition, i've opened the package and entered the cdkey on Steam. Except it's says only FNV, not the Ultimate Edition. Do you guys know how to contact Bethesda so i can get a good cdkey for the version i bought? Thank you very much.

I have the Ultimate Edition, it shows in my games list simply as Fallout: New Vegas. Right click and go to properties -> DLC tab, if you have them all then you're good.