New i-phone 4 not showing up when I try to sync to i-tunes

I just purchased the new iphone 4 today. When I came home to sync it, it said my desktop was too old of a model and I would need to upgrade. Called the store and they said I had to come back to purchase a Mac Box Set to upgrade. Brought that home and installed successfully. When I plugged my old i-phone in to sync first, it will only come up as a camera. When I open i-tunes, it is not showing up on the left side as a device. It's not recognizing it. They are telling me I have to either call tech support at 8 in the morning, or drag my desktop and phones in to the store at 9. I am going on a trip tomorrow and would love to get this solved tonight!!!! Anyone out there know how to tell me how to get the old phone to show up and sync it?