Samsung India — worst service centre

Address:

AKSHARDHAM APARTMENT, H NO 844, SECTOR 19 POCKET 3, Jamnagar, Gujarat, 110075

I went to TVS Electronics Limited, Ramphal Chowk, New Delhi 110077 to get my phone repaired.Phone was getting hang, apps getting closed & Phone restarting.
I requested them to re-install software(OS) also.
I gave them the phone on Saturday at around 3pm till Monday afternoon service centre didn't tell me the exact problem with the phone after calling twice on Monday evening they said its a motheboard issue replacing will cost 7000rs. I requesting them not to change the motherboard but re-install the software(OS) and charge accordingly.
When I went there to collect my Phone(GALAXY ON7) they simply lied and said that software has been reinstalled, I came back home and saw that they didn't re-install software !!!All the apps were intact even Wi fi configuration, Email login, Whatsapp etc. was there only.
They simply didn't do anything to repair the phone !!! ONE THING I DONT UNDERSTAND HOW CAN MOTHERBOARD GET FAULTY IN 1.5 YEAR ONLY. SAMSUNG IS KNOWN FOR THE RELIABLE AND STURDY PHONES
I have the bill of the service centre and all calls are recorded, I will raise this issue further and move to consumer court also.
Bill is attached for the reference
RegardsPranav Dutt Gautam