This is used so that as little contamination from outside bacteria enters the tube as possible. On a new tube it takes several pumps to begin with to get the product to the dispenser head. Once its there it pumps out on the first pump each time.
It is designed only to pump out small amounts each time for controlled use so that product is no wasted.
What may have caused the lack of pump action is that the top is not screwed on tightly enough, may be threaded on unevenly or may have loosened during postage, which can effect the vacuum pump.
Please unscrew the top and then re-screw the top again firmly.
If the pump still doesn't work please contact us again.