Hi, welcome to the forum, albeit with a problem.
I know there was a spate of people whose alarms kept going off, although that seemed to die down in recent times. I will look back on old posts for solutions.
In the interim, it is possible to lock the doors manually, just by using the keys - this keeps the alarm off. ALSO, if you look in the space between the passenger door and the dashboard when car is open, there is a button! Press it in, the red alarm light on windscreen comes on, then you can lock it using remote key and ultrasonics are turned off.
Hope this helps.
Stu