Registre en métal

I ordered 3 different registers and this is the only one that works. The other two are so tight that they don't move. The dimensions are also wrong; this is a 15 X 12 register, not 15 X 15. When I questioned it, I was told that the manufacturer could not answer my question about it. I know it is not the customer service person's fault but somebody should be able to get an answer.

Actual height and width is 12" x 13"