It's possible that because the money had already been claimed that it had gone off the system as far as the web tracking system is concerned.
At this point I assume they still couldn't trace the payment.
Then they say the money has been paid out......
It could be as you initially thought, just a Western Union blunder... I wonder......
The trouble is that some Filipinos think that we in the UK are so wealthy that this sort of sum of money means nothing to us and if her uncle did collect the money and pocket it, he would probably think that you would just write it off without giving it another thought, just like dropping a 5 pence coin in the street, then send another payment to replace it.
I don't know how true it is, but from what I've heard from various sources, this sort of thing is not really thought of as theft, it's just looked upon as a sort of family extension of the kano tax that we all come up against everywhere, everytime we travel to the Philippines.
In conclusion, all I can say is if you have known her long enough and you really trust your girl, just write it off, but make sure she gets her ID sorted out so that any money you send in the future will be and can only be collected by her. Better still, send her P5000 for the maintaining balance and get her to open a PNB account. Then you can transfer money directly into her account either through Western Union, Xoom or directly through PNB Europe if you open an online remittance account with them.
Cheers,
Iain.