Unexpectedly, it arrived! 
Since it doesn't appear to have been opened, I wonder why the delay. Two of the packets from the same US seller sent more than a month later had arrived much earlier.
The logistical system of post is very complex one. Few years back, a friend posted a letter for me from Spain. I was continuously tracking the letter from the day it was posted. After 3-4 days of booking, it showed the status as "Insert the item into bag", meaning that the letter is about to leave the source country. After this step, it usually takes a week or less (for most of the countries) for the letter to arrive in destination country. However in my case, the status remained same for almost 40 days and the letter arrived in Mumbai after 40 days!!! During this period, I was very worried as it was quite unusual and neither me nor my friend could do anything as the letter was middle of nowhere.

I indeed received the letter in good condition after almost 45 days, but I had sleepless nights because of it. I still don't know why did it take 40 days to travel from Madrid Airport to Mumbai...
One of my letter posted from Germany was first sent to Indonesia and then to India (New Delhi). The guy at German sorting center perhaps mistook "Indien" as "Indonesia".

Another letter sent from Germany was mistakenly first forwarded to Italy and then to India. So many interesting experiences of international shipping...Isn't this hobby really cool?

Aditya