India Post — Wrong delivery of my important medical bills

Dear Sir,
This is to kindly inform you that my mother had undergone a surgery on 17th March, 2023.
Accordingly, I have send the original medical documents and bills through speedpost on 28th April, 2023. On tracking the speed post consignment, it was delivered in National my office on 2nd May 2023. However, on enquiry it came to know that my consignment of medical bills was not delivered .Rather it was delivered in the nearby other office. Accordingly I have contacted the post man of the lodhi road HO and it's been 1 week already that I have not received any positive response .I want to raise complaint for wrong delivery against the post man . Kindly deliver my consignment at the earliest.