Another sure sign it's a scam is the requirement for you to obtain an "Expatriate Oath of Allegiance Certificate" (or some similar bit of paper you've never heard of). You can be sure they will offer to help you obtain that and where to send the fee..
In fact these scammers helpfully tell you that you can get one from "ZA Law Associates". Google found this reference..
www.scamwarners.com • View topic - ZA Law Associates; Gill Law Consultants. Fake law firms
ZA Law Associates; Gill Law Consultants. Fake law firms
by falnsb on Tue Oct 25, 2011 7:01 am
I believe that this company: ZA Law Associates, 33A Selborne Road, Ilford, Essex, London IG1 3AH is operating, or involved in, various scams offering bogus employment and immigration services.
The 'fax' number +44 (0) 75659 11657 is listed under various different scams on sites such as Scamwarners and is associated with a number of other apparently fake law companies including this one : Gill Law Consultants, 98 Woodgreen Road, Leicester, Leicestershire, LE4 9UE, United Kingdom.