EDEN - your motive for writing to the GB (to explain their un-scriptural practice of shunning) is the reason why a) you wouldn't receive a scriptural response, or b) you would be putting a noose around your own neck!
You cannot tell 'God's sole channel of communication on earth' that they are doing something wrong!!!
They'll either ignore you or "execute" you - don't waste your time. Do you honestly think that they don't know already?