Mira thermostatic shower leak - need advice how to keep it in place

abrr1000

Hoping someone might have experience with this - doing a DIY job as can't find a plumber who will come out and fix the damn thing.

We have a Mira Pronta Exposed valve shower. This is attached to a water pump.

Turns out the pipework was not correctly secured to the wall (watched a youtube video on how it is supposed to be fitted), so anytime the pump is turned on, the pipes move and it is a miracle that they didn't cause the shower to fly off the wall and flood the house.

Now we've done the necessary work to keep the pipes in place at the back of the shower (this is in the water tank press so easy access)
However, when we attached the actual mixer piece to the wall in the shower cubicle and turned the water on, there is water leaking out of the mixer piece and the water pressure is so strong that there is a chance it could cause the mixer piece to fly off the wall as it is attached by one screw to a plastic plate on the wall.

Any advice on how to keep the mixer in place securely and stop the water leaking out of it would be appreciated.

corkgsxr

What pump is it