You will likely have to contact an attorney. You bring up many issues which can't be sorted out here such as fraud. Your contract should have the terms and conditions you agreed to and I would start with that document. Understands what it actually says, because sometimes we read what we want to believe a contract says.
One thought, if adding a closet will satisfy your lender, it may be cheaper than your legal fees to pursue this and attempt to get your money back.
although most land contracts and rent-to-owns are written with the best of intentions..i have rarely seen any of them be an ultimate win-win for both sides....
there is typically a "can't satisfy" condition that has no escape provision to cover a possible future problem..
without even looking at the docs, i would assume a great real estate attorney could probably find something you could use to hold the deed holder accountable for something that was overlooked, not dosclosed, or some way of helping out your cause....i would be glad to refer one to you...please understand, that you still may be emotionally or financially satisfied even after you persue remedy...
i hope that helps.
Karen Paytas, GRI, CMS
Real Living Kee Realty