How can I force a franchisor to honor the franchise agreement or return the fees I've paid?
It does sound like you've got a point but without examining the agreement you have with the company it is not possible to know how strong your claims may be. In any case, here are your three basic choices:
1. Talk to the franchise company. You may have already done this but if not you should start here. See if they agree on the nature of the problem and are willing to work with you to solve it. Make sure you are clear that you are going to proceed to steps two or three if they do not do so.
2. Contact the government. You can file complaints with the FTC and whatever the state agency is that oversees franchise activity in your state. Frankly, the government probably won't be able to force a solution in any reasonable period of time but most companies will get serious about settling the issue with you just to avoid the hassles of dealing with the government regulators.
3. Get an attorney. Depending on the strength of your claim and the franchise company involved, it is quite possible that you can get an attorney that will take the case on a contingency basis. You'll be giving up a percentage of any settlement but you won't have to front the legal fees for the battle.