Warranty of Nissin flash - Comparing grey sets and local sets - firmware upgrade

[Nissin-RDP]

Currently, only Nissin flash purchased with local warranty will be able to get free updates of the flash's firmware. Grey sets from overseas or from non-authorised retailers will not be entertained at Nissin Service Center in Singapore.

[sumit]

Who are your authorised dealer in KOLKATA, INDIA.
It's the MEGACITY of INDIA & surprisingly no camera shop is having the product Nissin Di622 for Nikon.
They are constantly pressurizing to purchase SUNPAK PZ42X for NIKON.
Please let me know.....is it marketing????????????????????????????????????