Inverter split AC is not working since first season of use of AC.

We have purchased one split Ac(inverter ac) from Kaydee Electronics sec.18 (Company ‘Carrier’) ,Noida on june 2011.after one seasone of use of the AC,it was stop cooling. We made a complaint to the dealer but they told to register our complaint through customer care. Customer care registered our complaint and persons through frienchise of carrier at Patpargang industrial east delhi visited but they couldn’t rectify that.after that till this year after repeated complaint registerd there is no solution found.It is almost3 _4yrs. We are mentally torchered,since long time.therefore we senior citizens are requesting you to kindly look in to the matter and give us rahat.it is very costly Ac that we can not purchased it again.pls. Replace the AC immediately.