Bharat Sanchar Nigam [BSNL] — unwanted and adult links

Its been 2 to 3 weeks that i am recieveing adult and offensive message from bsnl. I have tried contacting the customer care and even opted for dnd but still my problem is unresolved and i constantly keep on recieving these messages. It has become so frustating and been a cause of constant problems. Furthermore it is not good to send adult links and contents (Without the concent of the reciever) as a minor may have access to it. On one end the govt is trying to ban sexual content while on the other hand bsnl is promoting these message (Adult oriented) and too on a massive scale. I request you to resolve my issue as soon as possible.
Thank you