How to Block Unwanted Commercial SMS on Vi?

Vodafone Idea (Vi) is a new telecom company formed by merging Idea and Vodafone to compete with the new market conditions in India. 

 Existing customers of Idea and Vodafone are automatically transferred to Vi. I have been using Idea network for the past eleven years and faced no major problems in their service.

 However, after migrated to the Vi, I faced a surge in spam SMS messages to my Phone number. It was a surprise because I had activated DND on this number many years ago.

 It seems that DND no longer works on my phone number once it's under Vi Limited. I am not alone in this, but my friends who were having Vodafone and Idea numbers face this sudden flooding of commercial SMS. 

 The only solution to stop getting these marketing messages to our Vi number is to activate DND once again. 

  Which is the Best Solution to Block Marketing SMS to My Phone? 
The TRAI ((Telecom Regulatory Authority of India) provides a solution to deal with spam messages sent by marketing companies. 

TRAI recommends every mobile user to activate DND (do not disturb) on their number. 

 To block unsolicited SMS from marketing companies to your Vi Mobile Number, you must activate DND.

  How to Activate DND on Your Vi Mobile Number? 
We can activate DND on a Vi number by two methods. They are:

  1. Call 1909 from your Vi number and follow the IVR instructions

  2. Send an SMS START 0 to 1909 from your Mobile Phone

How Did I Block the Spam SMS to My Vi Number?

I used the first method to block the marketing messages to my number. After calling the number 1909, I went through the IVR menu to activate DND.

Vi's automatic response informed me to wait seven days to implement my DND request to process complete.