Originally Posted by bostontrevor
If it's really a 1/8" cog and a 3/32" chain, it's no good. I'm surprised the chain even fully seats in the teeth. I certainly wouldn't ride it like that. I would take it back and tell them to trade you for a 3/32" cog as you asked, refund your money, or give you/sell you (at your discretion) a 1/8" chain.
Thanks for the answers, I'm going to have to order a new 3/32" cog. I still have the stock cog that came with the bike, but I'm prolly gonna get a Surly 18t cog instead. The bike shop will put the old cog back for me, I just have to wait until Saturday.