Aircel
Dnd service

Hi,

i have been getting a lot of calls from different vendors so wanted to active DND service. when i am sending START DND to 1909 i get a reply saying that this is an invalid option please enter start 1, 2, 3, 4... so how can i start the Do Not Disturb service in aircel?

thanks

Parha Sarathi Pattnaik