Tata docomo post paid connection
Activation problem

Hi

this is purushothama working for DRDO at C.V.Raman nagar Bangalore i had taken a post paid connection from TATA Docomo company through their channel partner by name Serco on 28/06.this is becouse they forced me take the sim by showing so many options. for which i have paid Rs. 300 as initial deposit to the person who as come for verification through the company by Serco, the bill number is 008582.After that till today i am calling the customer care people to activate the card but nobody is responding for the same. they are telling they are not responsible for the cause. Please help me to either to activate my sim or to refund my money back.thanking you