BSNL — dnd not working and unauthorised deduction

Hi,
My grandpa is using bsnl sim. He is getting the ad messages continuously despite the stop message sent. Also, it is taking all his recharge amount. He is not able make calls due to low balance. This is happening often. See, he is living alone. Think what will he do if he is not able to make calls during any emergency.
It is like we can unsubscribe only through his mobile. I did that many times from his mobile. Now i'm in a different location. He will not able to do all these by his own.

Please note that we are not interested in these ad messages and calls and disturbed during important times. Kindly stop all of these.
Can you please consider this and do the needful.