Jaquar — flush valves problem

Address: Sonipat Road , Rohtak, Rohtak, Haryana, 124001

Hi
Looking to the brand, I had used all Jaguar fitting in all my 14 bathrooms and kitchen totally.
The Flush valves are very disappointing. After use the never stops. Even with pressure pump the flow is very less in 2 flush valves. The service engineer has visited 2-3 times but problem still not resolved.
This time I myself stayed back to see what is the problem and to my surprise he said you need to get the flush valve kit changed on chargable basis.
When there was problem in the valves why do i need to pay and why the defective valves were not replaced by them .
Two taps have broken from the threads.
Four Plastic Handles of toilet Facets have broken .
Why jaguar should not replace the defective fittings ??
I did not find any special quality in Jaguar fittings