ADT Mississauga

I signed a 3yr contract (approx$450 per yr for monitoring) and specifically told the sales person that I wanted to own the system when the contact expires. He told me I could buy it from them in 3yrs. This wasn't written in the contract and I'm kicking myself because the contract says "equipment remains property of ADT" in small print. I've had no problems with the system...only problems with customer service. Now that the contract is expiring :), I'm trying to get ADT to tell me the cost of the system so they don't take it off my walls. They told me a year ago it was $599. They won't give me a price now and don't return my calls. The "Escalation Center" is supposed to call me now after I've already spoken to Dana, Natasha, Janet, Pearl. Two people in another province and various customer service people in the USA...that's where my calls were often transfered. Stay away from ADT!