Bharat sanchar nigam limited
Un wanted sms from 55500

I have been receiving daily 2000 (Appox) of cricket message for the past few week from 55500 without requesting or accepting the subscription for the service. I tried many time to unsubscribe by sms with an autoreply message which read as follows -

'You are not subscribed to this service'. The sms provider also deducts Rs.20/- month for this. I want the service should be withdrawn from my mobile with immediate effect.