water is too hot!!!!!!!

[IndiN]

iv had a thermerstatic shower fitted for over a year. since i had it fitted the water has been scolding hot. water had to be turned down from boiler in order to have showers

the plumber had the H & C water piper the wrong way round. have changed the pipes around recently. C wateri going to flow control and H is going to temp. the problem is still the same. the water is too hot to use..

Need help urgently any ideas??

both H&C pipes are gravity fed and are supplied from mains not a tank