Carrier Ac - AC Machine problem

Dear Sir
I am from Padappai- Near Tambaram
I was purchase Carrier AC *.* Ton Invertor AC from Sathya Agencies at Tambaram Chennai on **th MAY ****
and it was installed **th May ****. (Bill attached)
We are followed prompt free service from authorised service centre only and we found a problem in
out door unit (capacitor) was solved by service person within one year.
After two year , july **** we found second problem GAS Leakage from copper tube at inside of Out door unit
and it was service by authorised service with paid service RS ****/-.
You have to note down this point that AC purchased in two years only
Now we are facing(again) third problem that AC cooling not working properly due to GAS not available within Eight month
from the date of Above paid service of RS ****.Now again .This all the problems has come purely for unskilled technician,
They don't have knowledge of service.
IS THIS CORRECT PRODUCT? IS THIS CORRECT TO SPENT TO SERVICE CHARGE RS ***** FOR EVERY YEAR?
WE ARE TOTALY VEXED ABOUT THIS PRODUCT, NOW WE INFORMED TO SELLER OF SATHYA Agency.
WE NEED TO REPLACE THIS PRODUCT,