Hitachi Inverter Split AC Reinstallation and Replacement of AC

Hi Hitachi Team,
My faulty Hitachi inverter AC was to be replaced and its been 1 month since any reply from Hitachi team.
I had emailed mentioning the same with registered contact number ,but no reply to email since past 2 weeks. I have been writing on their Facebook page but there is no proper reply.
I am making multiple calls to the local service center,but there has been no progress on the replacement for the faulty AC.
I ma being harassed for the last 1 month on terms of replacing the Faulty AC and no specific date is being provided to me.
Is this the after sales support Hitachi provides?
Registered Mobile Number:-9434188784.
SPLIT AC – 1.2TR HITACHI MERAI 3100X INVERTER – R410A – RSG314HBEA