Bharat Sanchar Nigam [BSNL] — hungama services activated by fraud

Address:

Sri Ganganagar, Rajasthan, 335001

After lodging my complaint to bsnl that my landline is not working i received a call from a person that in order to get a complain number i have to send an sms bvas to 56677 and soon after sending message i started receiving sms messages saying
1. Thank you for registering bsnl hungama service.
2. User name and password
I didn't think much of it at that time but when i went on the said website and saw the services activated, i immediately deactivated the services so that i don't get charged but today i received the bill amount with 300rs extra charged for the hungama services. Now this is complete fraud and i don't know how these guys got to know my number and the fact that i've lodged a complaint, it might be that bsnl is giving them our info.
I have made my mind to disconnect my landline connection and would like to have some solution to this matter and my hard earned money back which those frauds charged from me.