Broken assembled Front Housing (cartridge) SNINASF

I have an Ultra 3/4 Dual Control Shower Valve Shower (Minimalist) installed in my Bathroom.



The temperature control knob has broken off. It appears that the central brass rod has snapped cleanly and appears to be unrepairable.



It appears that the Ultra Group Assembled Front Housing (cartridge) SNINASF part would replace the broken part but I have two concerns -



1) the assembly fixing holes appear to be different to the ones on my shower. Mine appears to have three holes - two at the top and one at the bottom. Will this assembly fit my shower?



2) I think the central brass shaft may have broken due to the mechanism sticking when trying to adjust the temperature from hot to cooler temperatures. My concern is that there may be another problem elsewhere in the shower which caused the part failure in the first place. What do you suggest in this regard?



Would it be more cost effective to purchase an entire new identical shower. Is this product is still available and how much for a new complete unit?



Your advice will be greatly appreciated



Regards



Nick