India Post — my letter not received by concerned authority

Address:

Palwal , public health engineering department, sub division 1 haryana

Please note that my order number is eh[protected]in and eh[protected]in is this, which was supposed to be posted to palwal public health engeneering department, haryana sub division 1. However on tracking it has been found that the letter has not been delivered and received by the concerned authority. It has been more than month since i posted. Please let me know status of my letter.