Airtel — activated and still I am getting 15-20 text messages from different companies

I am using airtel postpaid from last 2 months.
Dnd is activated - registration no is i[protected]
Still i am receiving sms from various companies everyday non stop.
I called many times to airtel customer care service however they were not able to give the solution.

I am receiving sms from below numbers:
Ax-walkin
Vk_flpkrt
Ax - isfsms
Br-timlab
Vk_bpojobs
And many more.

I have not registered anywhere for these messages. I did portability fro m idea to airtel, since then i am getting sms.

This is really very very annoying.