Complaint Review: DiVinci Sounds

This afternoon I stop for gas at the gas station on my way to home from University and these two men driving Navigator pulled over to ask me for a direction, then when i responded, one of them asked if i would be interested in buyin home theater system. They said they were they got extra shipment and even showed me reciepts and catalogue of the company's products. They asked for CND 500 for 800 wat system. I thought they were legit and offered CND 200, thinking they wont agree to it and will take off. They went back to their car and pretended they were leaving.... after 5 meters they stopped and one of them get off the car and said, OK i will take 220. I said no 200. They he agreed to it. After i got home i found out that this is SCAM. I am not sure, if there is something tha tcan be done about it, but would appreciate if anyone would advise on this.

Thanks
N.a.
Beaconsfield, Quebec
Canada