bro, are you really sure it's static shock?

do you feel the shock only 1 time (only once, when you touch the phone)
or all the time (you touch once, kena static, you touch 2nd time, 3rd time still got shocked)

i'm asking because you've stated 'while charging'..
static may also be present when not charging/plugged-in,
since the phone is statically-charged up by various movements.

if you experience the static shock only when charging up,
try these :

1. try another charger (loan other charger from friend/family).
2. try charging the phone at another place (instead of at home, try it in the office).

because it may also be due to improper grounding for the charger.

which case is that?

share your iphone6 pictar la bro..