Bicycle Mechanics - Stripped hole for water bottle cage

This is probably silly but I thought I'd ask anyway.

I bought a new bike and I was trying to mount a water bottle cage. I mounted one on the downtube fine. Then, I go to take off the screw for the seat tube mount and the bolt won't come out. It just spins and spins. I tried to vice grip the screw head to keep some pressure on it while I tried to spin it out but it doesn't want to come out. I don't want to take that bike back because a screw hole is stipped but what are my options here? Is the hole completely toasted now? Should I vice grip it and just muscle it out of there (if I can?) Do I need to cut the screw head off? I have no power tools so I would need to buy or borrow something. I'm guessing like a dremmel or something.

Screws don't strip when you loosen them. Did you put on the water bottle cage, or did the bike come with it already installed? If it was already on when you bought the bike, you doggone well should bring it back.

If it's a new bike, I'd definitely take it back and let them know what's going on. Its the bike shops job to make it right whatever that takes (and it may mean getting a replacement). I wouldn't use any tool other than the appropriate sized allen wrench because if you damage the paint or the frame, the bike shop may claim that the damaged braze-on was also the result of you using brute force or the wrong tool.

CMC

If it's an aluminum frame the water bottle bosses are like pop rivits. They can be tightened. I did this on Ten Wheel's Cannondale.
http://www.parktool.com/repair/readhowto.asp?id=147

Interesting Park tool link. I might need to start reading more of that site to learn some things.

I decided not to take the bike back about this since I had marred the bolt head with vice grips trying to get it out initially. I honestly don't think I would have been denied any help from the shop regarding this but I just didn't want to deal with the hassle of taking it back.

I ended up taking a hacksaw with a metal cutting blade and sheared off the bolt head. After I cut through I heard something drop down the seat tube (which I somewhat expected since the bolt was turning freely it just wasn't coming out the hole.) I took the seat off and tipped the bike over to have the rest of the bolt come out of the frame. It looked like it was siezed inside a threaded brass fitting. Maybe this was the rivet referenced above? Either way for the time being I just took a zip tied and cinched the top of the cage down and used the bolt for the bottom. Seems solid right now. Maybe I'll look into doing a proper fix down the road if it proves not to last.

Thanks for the help.