India Post — loss of my speed post

Address:

Papum Pare, Arunachal Pradesh, 791111

On 19th july 2018, i had sent one speed post bearing no ew[protected]in from the ranipool, east sikkim 737135, addressed to the office of directorate of elementary education, itanagar., sainik school east siang arunachal pradesh 791111. The same have not recieve by the address to this day. I tracked on online, its showing already delivered but the concerned person did not recieved till date. I do not understand the loss of my speed post. This postal had to reach on 30 july 2018 but still not. I have my interview on 20th august 2018 but still concerned person could nt recived. So kindly look this matter seriously.