First Flight Couriers — Delay in delivery and staff not answerable

Address:

Nainital, Uttarakhand, 263139

I have sent a courier through First Flight on 16/08/2016 (DOCKET NO. FW0038774) from Haldwani to Singapore which consist of my college documents.
At the time of booking i was told that it will take maximum 6 days to get it delivered. Now when i called up the delhi office to track it, the staff person is not answerable, they told me we don't know when it will be sent from delhi.
I want the courier company to give me a fixed date of delivering my documents