Executive Chairs

Hi I bought an executive chair and tilt.But Lombard can not help increase height.please my fault or is broken chair? Lombard is a chair in the box just a bit internet.Erm paper.It gaslift says is growing, but I can not find a way to get over now I've added the top half of the heavy section of the wheel I can not lift.Arghhhh If there is a lever on the right side should be the height and tilt to the other. If only one that has been Punk'd: P There should be a lever or button underneath.but requires great weight on it, pulling the lever or not win the promotion. Check the manual to see, and if that does not work full contact with the manufacturer of the chair may have been a plastic / rubber cap on the button that operates gaslift should have been removed before putting together.