Kent RO — Service charge during free service period

Address:	GALIBPUR BHITI MAU UTTAR PRADESH
Website:	Kent RO

Dear sir

Today I called the dealer for service of my Kent purifier, he serviced properly but charged me 300 extra as service charge. My purifier is under free service period but he said it is only if you booked online through App for service.
This is fourth time service has been done through the dealer on call as my parents were on home alone, and they didn't enquiry much about the service charge and not using smart phone to lodge service complaint through APP. Is this necessary to use smart phone to purchase your company's product?

Regards