My past employer in guam is denying my 401k although I have every paycheck showing the money contributed through payroll deductions now I'm back in the U.S. what can I do

Who is handling the 401K... I don't know of ANY employer that does it themselves... they are all if not almost all run by outside financial organizations. You would have been getting quarterly statements from them.

401K ( at least in US) is not handled by the employer but done though a admin company.
So who was handling yours ?