Did you try filling it with a slow trickle of water? I find if there's too much water pressure, it will just push all the water out of the WT. If you use a very slow trickle and fill to Bottom left corner of the C in the word "Pinnacle" which is about a cm below the top of the inner perc chamber, I find it works better. Also, if sometimes a little water gets trapped in the upper chamber, you can shake the WT a little bit and that water will go down and fill in the last bit of water in the bottom, the WT really takes very little water and the small orifices have surface tension in the openings that make it hard to fill. When I first started using it, I also thought it was broken and when I didn't fill it high enough to where I mentioned, it wouldn't perc very well.
Now I find it works great and I can even use it at an angle and it won't spill. But be careful if you feel the urge to cough and don't exhale or cough into it or you will push the water through the bottom and spill it into the PnP. I just barely pulled my mouth away once, it was a close call.
Also, I got my WT from this discount sale and my unit seems perfect, no blemishes.