Generally, you have four years from the time contract is breached unless agreed to by the parties to a lesser time not less than 2 years.
Hopefully you have something in writing and have been receiving payments which may be easily traced (not cash).
Additionally, the terms of the contract dictate when he must pay back the money - not the statute of limitations. The statute of limitations is the amount of time you have to file suit once a claim has arisen (generally speaking).
