I am going to suggest a slightly different approach, which is to keep the credit card option as a backup, but try to resolve it with him first. I'm with the people who think you should just return the frame -- you are in a position where you are going to need really good customer service now to make sure that you get what you ordered without having to wait a very long time, and this guy has demonstrated that he is not going to give you good customer service.

But the way I understand it, you can't dispute the credit card bill until you've given the merchant a chance to make it right. So you have to go to him first. I wouldn't, if it were me, give him the option of fixing the frame; I'd first make a list of all the things that weren't done (was the bridge moved to accommodate fenders? I didn't see if that question was answered), and then I would write him a letter listing what he said he would do vs. what he actually did, and then I would ask for a return shipping label so that you can return the frame. I would send that letter certified mail along with copies of anything you have in writing (including e-mails).

I might also e-mail or fax him a copy of the letter so that it gets there more quickly. Give him a deadline, as well: you want the return shipping label within two weeks and you expect to have your money refunded within 30 days after you return the frame. Don't be snippy or snide, just be very matter of fact. That works best in these situations.

He will probably comply. Most business people do when they get a certified letter. If not, wait out the thirty days, and then take it up with your credit card company. (You might want to call them to verify any time limits, but I am pretty sure that they are going to require you to attempt to settle the dispute with him first.)