Phone Will not turn on, Will not hard reset?

I purchased the Galaxy S vibrant from Bell about 2 weeks ago, after a full charge this morning I had the phone turned on for about 3 hours and when I took it out of my pocket the phone was turned off

When I pressed the power button the phone goes to the Galaxy S black and white startup screen for a few seconds then shuts off, no sounds or animation of the S logo.

When I plug the phone into the USB charger the loading animation shows up for a few seconds and then shows the battery for another 2 seconds then dissapears. It almost seems as if the battery is screwed up somehow?

I tried the hard reset but when I press the volume down, home and power keys it goes to the little yellow caution symbol that says Downloading, do not turn off target!!!

I have no idea what is going on and why I can't do a hard reset at the least and I haven't found anybody else with the same problem as they can at least get to the hard reset.

Anybody have any Ideas? I'm getting really frustrated and If I have to send a 2 week old phone away to be fixed for 4-6 weeks while i'm paying 62$ a month for something I cant use I am going to lose it!

Also, connecting to Kies to do any updates etc won't work, the computer picks it up for a second but the phone won't stay on to do any updates. The battery and sim card have been taken out and put back in a dozen times. The phone is not rooted and running 2.1.

Exact same thing happened to me about a week ago. I have replacement insurance with Best Buy and they had no stock to replace my phone but should have them today. This will be the third phone, first one wouldn't hook up to Kies it just kept looping.

Sorry, I had read those....Volume up, power and home doesn't work.  Volume down, power and home key is the only thing that works and just hangs at the downloading screen.

I tried a couple more times, still doesnt want to go past the black and white start screen. What first method?

Anybody know what the phone is trying to do when it goes to the yellow downloading screen that says do not turn off target? I said it hangs there but maybe it could be just downloading something through wifi or 3g? How long should it stay at the downloading screen for? I had only let it sit for about 10 minutes before and then was thinking it could be racking up my 3g data usage.

that's the bell vibrant and after the JH2 update it does the hard reset just like regular I9000s. There seems to be more stock available in stores so you should be able to take your device back for replacement not a send away repair.