Also, if there are no cashiers available, I generally go and ask for one and most of the time, they open a till or put it through the self service for me.
If they don't, I leave my shopping and go but appreciate not everyone has the time to do this.
Good grief. Talk about cutting off your nose to spite your face,
Also insisting that someone leaves what they're doing to open a till for you is pretty entitled behaviour. Not to mention the work that someone else has to do to put all your shopping back if you leave it.
You're clearly not really thinking about the staff, because your actions make their life harder.