ICANN is directly responsible to the registrars and not to the third-party resellers of domain names. That being said there is definitely a need for ICANN to check up on the down-the-chain members of the domain name game to make sure the system is functional and honest. Somebody needs to get in gear and stop these many troubles, and ICANN is that organization!
ICANN should be the "rock" that anchors the whole kit and caboodle of Internet domain names firmly to reality. As the main source of authority concerning abuses and problems relating to disputes and bad/dishonest business practices, ICANN needs to be sensitive to the fact that businesses, especially small ones, rely heavily on their name to remain solvent and successful. Many larger businesses have multiple domain names and other presences that allow them to more easily weather stormy domain name seas that would sink or bankrupt a smaller operation.
ICANN needs to step up to the plate and be cognizant of the importance of its role, perceived and actual, in maintaining a level, orderly field of play for all the domain name customers, starting with registrars and resellers. By holding them to their contractual obligations and penalizing or revoking their privileged position, ICANN has the ability to help eliminate many of the rampant problems just by enforcing existing guidelines.
I would certainly make sure to report your abuse issues to ICANN and see if you can get a reasonable resolution to your problem. If they don't know, they can't help do anything to fix it. There may be a legal way to pursure this resolution, but cost and time appear to be of the essence in your case, so a lawsuit might not work for you. Good luck and let us know how it all turns out.