Samsung — Product under warranty but they are asking money

Address:

mohanpur bareilly

Hi
this is chishti and i purchased an ac which is under warranty with 5 years period. the ac is not working so i called to samsung support the the engineer came and check and took money as service charged and he told me to pay for parts although part is under warranty. i need to fix this issue, because when ac has a warranty then why i will pay to them?
please solve this,
thankyou