You need to press the brake first. That puts the car into ready mode. Only then will it accept the command to turn off these functions.
If you have the front collision assist turned off then you will see, in yellow, a wee graphic of a car that has smashed into something on the top left of the driver's screen. Also if Lane Assist is off, that icon shows yellow. I go nowhere if Lane Assist isn't yellow.
But seriously, this is no joke. If the thing is activating as often as that there is a fault with the system, and a bad one. I have the identical car to yours and it has activated twice in ten weeks, both times for what was probably an understandable reason. Your dealer needs to address this.