My suggestion is to contact your Buyer Agents manager and discuss your disappointment. They may assign you another agent or release you from your agreement. Depending on your agreement, there may be a fee to terminate.
Regardless, I would suggest you have representation - a real estate agent or an attorney - to oversee your transaction. If you think the real estate agent fees are "hefty" - wait till you see the bill from the attorney!
We are sorry about your situation. Our recommendation is to contact an attorney to have them review the document and advise you of the best course of action.
Any advice without the capacity to review this document would be purely speculative.
Every state agency agreement is different, so read yours carefully. The first step, I would think, is to have a discussion with the agent, asking to be released from the agreement. Be candid with her, and simply say that the agreement is simply not what you thought it would be and you want to move on. If necessary, also ask to speak to the broker. In my state, any release has to be in writing, and the broker has to sign it.
As to what the builder is saying, remember your grandmother's advice: If it sounds too good to be true, it usually is. I have found that in the majority of new home deals, it is really in the buyer's best interest to be represented- After all, the builder does this for a living, and understands and may even have his own sales agreement that is slanted in a seller's favor.
Hope this helps-
Accredited Buyer's Representative
Coldwell Banker All American