How to ACTIVATE DND in BSNL ?

Hello Everyone,

BSNL is the Only Operator which is Just a Disaster in every aspect.

So, for a Few Months, I have been getting Tremendous SPAM Calls/SMS on My BSNL Number and I searched for Deactivating it!

"START 0" to 1909 this is how you can activate the DND of any Operator including BSNL this is what internet articles and BSNL So-called Customer Care who doesn't care about anyone!

Then, when I send this SMS I got an SMS which is like Categories, Modes, Timebands, etc...but I want to deactivate it completely, so I again installed TRAI DND App (ONE THIRD CLASS APP) then also it didn't help but it was working for activating/deactivating the other operator's DND Service like airtel,jio only BSNL is the problem!

PLEASE TELL ME HOW TO COMPLETE DEACTIVATE THE DND IN BSNL