Panasonic — Complaint not resolved after 18 days

Address:	Kolkata, West Bengal, 700060
Website:	www.panasonic.com/in/support/contact-us.html

I have logged Ticket #R[protected] on 7-Aug. Panasonic service center technician came to my house on 8-Aug and took the part (PCB) for repair/replace. That time it was under warranty and I was told that within 3-4 days they will repair/replace that part.
It's been more than 18 days now, I have neither received the part repaired or replaced. There is no update from Panasonic why this ticket is still unresolved and unattended.
How long does it take to replace a part? One month? 2 months? Company did not give me any clear answer on this. Will it be replaced? If yes, when? If they cannot replace the part, why they are holding it. They should send me in writing that they are unable to do that. They cannot make a customer waiting for infinite period for a part replacement.