Robinet pour salle de bain avec ensemble de drain central à 536-DST

It was installed in my new house 8 months ago. and is already damaged and tarnished.

We have had the tap over a year and it continues to frustrate. The way ours is set up the left side is hot and the right side is cold. We find if we run the tap for any time we get either hot or cold but no blended flow to enable fine temperature control. Beyond that if we attempt to close off flow pressing down from the hot side it leaks. Closing down from the cold side (MOSTLY we remember to do this) it can be fully closed. It has been like this from day 1 and caused me to drop the plumber who installed it - he offered to take it out but I declined as it seemed extravagant. But over time it is just a poorly built tap with very poor control.

I did a temporary fix of the inside of the handle with pliers to squeeze the metal back together, but there is no way it should break this easily when attached to a plastic stem.