I signed a contract with Northstar for 36 months at theedn of 36 momths I proceeded to cancel the contract, or so I thought. In there contract is a clause stateing if you do not notify them 3 months in advance they will extend your contract another 18 months. Its states cleary on my copy that it expired at 36mo. BEWARE they are trying to collect another 18 mo. which I offered to eve send there alarm system back