Radiator isnt getting hot?

We just had a new boiler installed 2 months ago. Our one bedroom (which never had problems with heat) is not getting any heat. I bled the radiator and cold water flows out? All of the other radiators in the house spew hot water and the pipes are hot. We had the heating company who installed it come back out and they claimed "there is an air pocket", and they never fixed it (5 year warranty is good for what)? Anyways, I was wondering if anyone has encountered this problem and is there anything else I can do??