CAD/CAM Mill for Dental...Lemon law?

I leased a CAD milling zirconia system Jan 06 from a local company in California. System is about $60K. The system has been plaqued with problems from the beginning. The manufacturer has admitted the issues and has been supporting the machine but after 2 years it is developing problems and breakdowns that are causing me delays in my production, if not all out failure to manufacture what it is designed to do.

The company has developed new software that drives the system and has admitted the sofware that came with the machine was a problem. The new software requires an addtional scanner ($25k) for it to work with the system.

The company has been promising me updated software for about 11/2 years and now I am told it will come at an added cost.  I have told them they need to retrofit the new software with my present system without any new hardware and they are researching it.

for 3 months I have had daily failures and breakdowns in the system, their software, hardware and even the materil this machine mills. I am at this point considering giving it back to the leasing company and declaring it unusable for the purpose I bought it and cancel my contract.

My questioin is that if the company cannot support a machine after two years of failing to get it to perform as it was designed to do can I invoike any lemon law or legally give the machine back and cancel my lease contract.

any input will be appreciated