My Digital shower is not working properly?

When I turn the shower on the boost button comes on as well and cannot be turned on or off. The pressure is average not like before when we used to turn the boost button on. Now the shower on/off button doesn't work and the shower will not come one. Then the shower started to come on by itself with no lights on and now we cannot turn it off!!!1

I have turned is off from the mains and the shower is still on.

Please help!!!