BSNL Post Paid CellOne
Unsolicited sms from 55500

I have been receiving daily dose of news for the past few week from 55500 without requesting or accepting the subscription for the service. I tried twice to unsubscribe by sms with an autoreply message which read as follows -

'You are not subscribed to this service'.

I want my mobile no. to be unregistered from this service.

Thanks in anticipation of your assisstance.