DTDC — what about my parcel

Address:

Pune, Maharashtra

I am send my envolpe from sangli to Bangalore. That time courier office boy in sangli tell me within 3 day he reach their, but not reach their.my pob no-(POB no[protected] dated 14/05/2014 by DTDC).this courier rech at 20/5/2014.tell me how is is responsible for my loss.i want explanation on written.