I had similar issues, but recently got paid. Here is what I did, I'm not sure which of these helped.
- switched my payment option to go directly to Paypal so they no longer hold any money
- redid the tax information
- suggested on the forums that everyone in this situation should work together to make it into more of a story
- explained that I would be considering taking further action if the matter was not resolved swiftly
My feeling is that a combination of redoing the tax information and putting a little pressure is what helped. I don't think they are acting in bad faith, it's more that they do not seem to have the time and resources to deal with the issue properly. Clearly this is not good enough on their part, since the share they take from developers is ultimately what keeps them going.