Please Help! iPhone contacts deleted! Cannot retrieve via back-up

Hi,

I synced my iPhone 4 for the first time today and the first thing it did was back up my phone (I've had my phone for 5 months). I then selected the option to sync contacts and calendars (via USB not iCloud) with Microsoft outlook. It synced fully. I disconnected my iPhone then reconnected, at which point it began to sync automatically, it was taking too long and I was running late so I cancelled the sync, ejected the iPhone and went on my way. My contact list of 3000 (majority business contacts) now is missing 70% of the numbers and other details while the names remain on both my iPhone contacts and Outlook contacts. I have tried to restore via the earliest back-up file that shows up and nothing! I appreciate any help you can give! I reallly need these contacts back immediately!

Thanks in advance!