Hi, don’t suppose anyone can help.
Our bath tap is also the tap for our shower. It’s a thermostatic tap. So the right (thermostat) side is fine and works well. The left side controls the flow of water.
The left side broke yesterday and went from turning stiff to loose without releasing any water (luckily the taps were off otherwise it would have broken full flow!)
And now it’s just loose no matter which way it’s turned and just keeps going around and around.
Quite worried as obviously we won’t be getting a plumber out anytime soon. I expect they’ll be fully booked all week anyway! 
What can we do? Heeeelp!