India Post — lost of kvp by post office staff

I have two kvp which was matured in august 2017. I submitted all the documents with fir copy because my original documents has been stolen from my house so i request for duplicate certificates and submitted all the documents two times to the respective office but not received my money till now. Not only this again the staff is saying my documents has been lost so i need to submit the documents again. Before this they told me my fe has been sent to rohtak for process and when i asked them they said they have not received my file. Iam 63 years old widow and just fed-up of the response of the staff and now i don't have any other options except complaint take strict action against them otherwise i will escalate it at higher lever. It's your staff mistake why i need to suffer just because of them.