All data missing after syncing new phone

Windows Mobile 6 on a PDA - HTC PPC2800, Windows XP

I needed to send my PDA off for repair, to be temporarily replaced with a
new phone, exact same model.

I synched before taking in the old phone, and synched when returning with
the new. (It was set-up as a new device.) NONE of my contacts, calendar,
tasks etc are to be found. When going into Outlook, there is no info there
that was from my old phone. (Only files and a few deleted items.) As I was
never using Outlook regularly, and the AutoArchive was set to 'prompt', there
was no archive.pst file.

I don't understand how my info could have disappeared, as the Bell rep said
it shouldn't have been overwritten by 'nothing' from the new phone.

Signed Panicking in BC