Janelle, I'm so sorry you got taken...what happened to you is EXACTLY how the scam works...they keep asking for money until they suck you dry!! Think about it: $775 times 2 times = $1,550...almost a 1/3 of the amount of money you need...then add that $554 they wanted to find you another loan...and you're halfway to the original loan amount of $5,000. WHY would anyone pay half the amount of a loan that they're requesting? Once in the trap, you don't question it b/c they make it sound real...then b4 you know it, you're in too deep!!
They get you, b/c they have you wire it out of the country, and then there is no way to retrieve it.
BTW, Walmart doesn't use Western Union, they use Money Gram. File a report with Money Gram, the police, the AG, the FTC and the OCC. Please let us know if you do get your money back. I haven't heard of anyone being successful in getting their $ back. Good Luck.