Please help, contacts lost

Hello to the forum. We have a very serious problem. We bought an iphone 3g today, and already had an iphone 2g. So we wanted to sync the contacts in the old iphone to the computer so we can transfer them to the 3g model. We checked on the info tab in itunes, and chose to transfer the contacts to windows address book in outlook express. We already had about 40 contacts in the outlook address book and we thought that the contacts from the phone would transfer automatically to outlook, but instead we had 300+ contacts from the iphone deleted, and replaced with the 40 useless contacts. We still have some numbers on the Sim card, but since iphone doesn't save the numbers on the Sim card, a lot of numbers are gone. Is there any way we can restore them? If there is, please help.