Thrash her
Or give her the bill 
I really am pissed off with it mate, i mean REALLY.
She really doesn't give a flying duck, and simply tells me to stop going on about it.

I turned it off at lunchtime with a snarl as it was so hot in here then, but it was back on full blast when I just got in now.

Going to have to leave the 'puter now as it's just too hot in here, even with me jumper off.
'Kin staggering that anyone can think this is 2SSSSSSSSO cold" in here ffs.
Think she needs to go to the quacks if that's the case.