Builder Denial/Created Monopoly

Looking for information on other codes I can use as I file a lawsuit against a builder who denied me credit for a mortgae as I did not use their lender.

Long story short, I attempted to use their lender, he gave me a crappy deal. I gave them a prequalification from another lender, they put me on the list only to deny me for language in their sales contract stating I must be approved by their lender.

I have written my first letter quoting the Sherman Anti-trust Act which deals with monopolies, Clayton Act which ties contracts together and the FTC quuoting unfair & deceptive business practices.

Does anyone have any other specific areas I should look to include on my notice of intent to file lawsuit? I know builders/lenders get kick backs & this is also securities fruad by making me go thorough another approval process.

Any leads would be greatly appreciated! TIA