Agreed. When I first started playing and saw the "stay online to unlock this slot for free" on the right side of the warehouse, and saw it was not free, but cost gems...
I put a ticket in with billing support. Got the usual form auto-replay first. Countered with the statement "This looks alot like false advertising and bait-n-switch". Interestingly enough, 2 days later that little "unlock for free" was gone.

Can't say that my ticket and response were the reason that they changed it, but it was an interesting coincidence on the timing. Just saying...