At the time of purchase they tricked me into buying Lojack. I realized my mistake later on and tried to cancel but they wouldn't let me. They said since it has already been installed, it is too late to do anything about it.
Do you have any suggestions if there is anything else I could try. Thank you.

 

If you already took delivery of the car, you may be out of luck (and your money). Those dealer add-ons are pure profit for them and there's almost no chance you are going to get your money back once they have lined their pockets with it. Good thing you didn't fall for the undercoat, scotchguard, and paint protection warranty. Just consider it a lesson learned. If you still have not taken delivery, just cancel th whole thing.