You're only eligible for the working payment if you paid tax in 2007-2008.
I worked for 4 months, but I didnt pay any tax and was told that is the reason I am not getting it. But, if you didnt get all of your tax back, then you could be eligible. You just have to keep waiting. They're making payments till mid-may, so if you still havent got it by mid may, then give them a call and ask where it is.