Baron Toilet

A little over 3 years ago, reno 1 bathroom and replaced with Baron. Don't remember the model. Worst choice ever!! They said the they use the Geberit system which is good European quality etc etc etc . About a year ago had issue. Water from tank flowing into bowl. Called them and they replaced the flush valve. Now , again same issue. I think its the fill valve this time . Tried to fix ourself but no use. Calling a plumber is so ex! So to all out there STAY AWAY FROM THIS BRAND . While trying to find ways to fix checked out a few videos and even some of the plumbers say the dual flush, push button, "modern" type are not so good quality.