Gloria - The Genos you purchased from Guitar Center - Was it "used"
?? IF it was brand new, those "missing" items should have been in the box, on the bottom, underneath the keyboard .... Did the box appear to be "opened" but, taped shut? AS if, the Genos was previously out of the box, and they put it back in the box, taped it shut?
It "almost" sounds like you may have purchased a previously returned item ... It's very unusual to find those primary parts, missing .... AT LEAST, though, you got that straightened out and will receive whatever you need in a few days from Yamaha....
I, however, would be more concerned about the possibility that you purchased a "returned" keyboard, and they turned around and resold it to you at FULL cost ... especially if you were not aware of that fact.... I would NOT put it past Guitar Center (ANY of them) to pull something like that....
They "want" you to buy whatever is hanging on the wall - BUT, all the punks go in there and mess with all those guitars ... and technically ... they are NOT NEW anymore ... not when people can come in and grab them off the wall and sit down and play them for hours! Not any different than me coming home from work, taking my guitar out of the case, and playing it for a while ... and then putting it back in the case...
So ... for that matter. I always ask for a NEW one in the box ... take it home ... try it out ... and if I don't like it ... bring it back... no problem....
IF you wanted to, Gloria - You, technically, could take that keyboard back ... return it ... and tell them, you want a NEW one that includes ALL of the pieces .... OTHERWISE, give you your money back....