Hi, The Case looks interesting to me. I am trying to analyse it from both sellers and buyer's point of view.
1- I have a thing against buyers who leave negative without even contacting once. Negative Feedback is like a bullet, it can kill you and also it will never come back if once fired. Shouldn't E-Bay make it mandatory for buyers leaving -ives to first contact seller and that apply for a negative feedback. I dont think there are thousands of negative feedbacks being given daily. So it must get approval from an eBay team.
2- And for the seller First get a list of places you dont ship from your courier agency, post it on your item description. But still if a sale is done you should always try to complete it. I am not really digesting the excuse of sunglasses safety thing. Blue Dart is there to ship such items. If even that is not available use speed post. You can buy 20 Rs Thick Thermocol. Make small pieces and pack your glasses safely in it. It wont break even if someone steps on it.(I did this when I sent a wine glass to a friend with speed post.) My friend a little we all have to bend in some special cases. These things dont happen daily. A little extra 100 Rs wont take a big toll.
Currently I see that you have got the feedback revised to neutral but just think the loss of sales you would had to bear when buyers would have scared away seeing the negative feedback. Neutral isnt good either
Also One last thing I would like to add, Majority of the sales comes from the new buyers who are shopping for the first time. And with little knowledge of feedbacks and DSR's they have It's like putting AK 47's in their hand and telling them to shoot bull's eye with it.There should be some criteria for leaving negatives and low DSR's.
Just speaking my mind off, If I offend someone do forgive me.