Yesterday I lost my Sony Ericsson mobile handset. I called the SIM operator (Vodafone) to block my phone but I was told that this is not possible.

I've heard that if we provide the IMEI number of the headset along with a FIR copy then the operator will block the handset to prevent any misuse of it.

Isn't Vodafone stepping back from their responsibility ? Please help me in getting my handset blocked and to take an appropriate action against Vodafone.