Samsung — negligence of service center

Address:

Ahmedabad, Gujarat

Given my Galaxy Grand Quattro at Service center, Grand Mall, Ahmedabad on 17th Jan'15 with Complain of Camera. the same was handled by CCO, Ms Anita and Technician, Anil. cleaned the camera and stated that rubber linning was missing which causes the dust. checked the camera and taken the mobile. PLEASE NOTE THAT THERE WAS NO DOCUMENT GIVEN IN THE TIME OF DELIVERY ONLY 2 FORMS(NO KNOWLEDGE ABOUT THE CONTENTS ) WERE SIGNED BEFORE THEY TOOK THE MOBILE. when i called from the mobile, found outgoing voice was disabled and my voice is not been transmitted to other mobile but i can hear the voice. again went to the same service center and had same process, but not they told that i have to change the mother board. MY QUESTION - I HAVE GIVEN THE SET IN WORKING CONDITION, THEN WHY I HAVE TO SUFFER ?