I discovered a rather odd glitch on the system
When I disconnect it from ac power, the battery icon switches from the charging icon to discharging battery icon for a few seconds, then switches back to the AC icon on its own (status: battery not charging, power source: Power adapter) :O
Called Apple Support.. given the relative complexity of the case (International DOA - Dead on Arrival i.e. Borked Out of the box) it took over 1.5 hrs
After a bunch of transfers from within their Bangalore office, they finally transferred me to a L2 senior customer relationship guy in their sydney queue
The problem is either with the battery or the system itself.
I now need to go visit a Apple service provider in Chennai
They will swap the battery to confirm if it is a bettery issue (hopefully), if yes, Apple will replace the battery immediately
If it is a system issue, they will start a DOA replacement process (which may take 2 weeks though)