We're in the middle of trying to get out of a contract with our printer supplier because the thing keeps breaking. We've had to have the fuser unit replaced at least 5 times since we got the machine in November 2012. Other problems have also come up - it's currently out of commission, but I don't know what part needs to be replaced this time.
Just plain old breach of contract?
I would suggest to stop making payments for the contract and start negotiations from there.
On the other hand, if you go through a cartridge of ink in a day, that says to me that either the cartridges are very small, or you print way too much for the capacity of the printer.