Also another tip to shut the alarm off is the following: Open passenger door. Lock the car by using the button on the console. Shut the passenger door. The car is locked and the alarm is off.
You can have good night rest when the car is indoors or something like that.
When you switch on the ignition the alarm stops??
My car has the original alarm and also an extra one for the insurance company.
I have disconnect from the original alarm the claxon. This because alarm 1 sets alarm 2 to work. It always gets on when I don't like it. So I changed it a little bit.
Good luck by finding the solution to your problem. Maybe an electtronic switch has been damaged?