I have the same problem and the exact same messages. Sometimes I get the message that I am already in DND. I tried to de-activate and activate DND also - no use. As a result I get a minimum 10 SMSes and 5 spam calls a day.
Go to
Telecom Commercial Communications Customer Preference Portal and input your phone number and do the search. It will show you what operator you are listed under (no one cares what your actual operator is - what is listed in the trai site is what it is)
I ported my number from Vodafone to BSNL about 3 years ago and it still shows Vodafone when I search my number there. I have written on
National Do Not Call Registry , twitter, DOT, Communications Minister, Secretary, concerned IAS officer multiple times. No use. Theres only that much we common people can do