Geberit India — wall mounted tank

Address:

600061

Purchased 4 out of which 2 are not working properly. Purchase and installation done by contract builder... Who himsel[censored]nable to rectify the error. Pls helpthe friction is loose.
It gets stuck often... Water keeps leaking... Also the pressing bitton the friction is less.. It gets much inside and then the water comes to flush.. And the flushing quantity is unlike the othed two ehich have no prbm from day1

It was purchased last year by the builder whom we gave the contract to build..4 were installed out of which 2 both on the same side of the floors have problem.. The washrooms above and below.. Pls eectify asap coz i have my bedridden father.