If you are thinking about applying for this don't...I was sent the same letter, and didn't fall for this one bit.
No one should have to pay a fee upfront... That should tell you something right off the bat as to what type of "membership" or "company" you're dealing with. I am not a member of a workforce Union but received this letter in the mail regarding a $10,000 credit line. Read up on this matter and don't subject yourself to this pitfall!
However, if you have gone through with this and are looking for help... Contact the Attorney Generals office, and speak with Consumer Protection.
Also, report them to the better Business Bureau, and let them know how you feel.