How to stop Lenskart promotional SMS ?

I am a regular customer of Lenskart for my supply of contact lenses. But truly as you mentioned, Lenskart has been sending too many messages these days. It gets to an annoying level.
There are a few ways with which you can unsubscribe the messages from Lenskart.
Via their website
Once you login to your lenskart account, you can find the chat option at the left hand corner. You can get in touch with the chat executive and submit a request for the unsubscription of your messages. Generally, the messages are unsubscribed in 72 hours.
By using phone line
You may call the customer care at 9999899998 and submit your request to unsubscribe you from the promotional messaging. It normally takes two working days to complete your request.
Using email ID
Shoot them a mail at support@lensakart.com indicating the issues you have been facing with too many messages. It too takes around 72 hours to get your request being processed.
Use their Facebook page
This seems to be the faster option than all those mentioned above. Their Facebook team is quite active. You may choose to send them a message to the effect. Alternatively, you can also post your concern on the page itself. It has been observed that the promotional SMSs are deactivated within two hours. The link to their Facebook page is https://www.facebook.com/Lenskartindia/
You may also use the DND services from your telecom operator, but the step may cause even the important messages being turned off.

If you want me to share my experience, I tried all these methods and it worked for me. But since I used all of them together, I could not make out which option worked quicker.

Lenskart is acquiring the SMS and Email database without taking consent of the people. They are buying the email and phone number data base so this makes it harder to get out of their list.

As most of the time the campaign blast made are random and doesn't allow you any form of opt-out. You can only opt out if the campaigns are blasted from official lenskart numbers.

In case of Unofficial Marketing campaigns

If you have got the promotional messages from such unofficial marketing campaigns then you have to contact the customer support. You can reach to them at the following email address: support@lensakart.com. You have to explicitly mention the case and the numbers from where you are getting the campaign messages.

In case of Official Marketing

If you're opted in official Lenscart promotional funnel, then here's something you can do to opt-out.

1. Call Customer support at : 9999899998 and ask them to opt you out of the promotional messages.

2. Use messaging feature on phone. Type LENS and send it to 567678. This takes 48 hours to get you off the list.

3. Go to Facebook page and send inbox message to the page to opt you out.
URL: https://www.facebook.com/Lenskartindia/

Make sure to ask them that none of the methods worked to opt you out. How to resolve the issue. This will get the issue to their higher support channels and you'd be able to remove the number.

Unsubscribe if worked then within 24-48 hours your number will be removed from the registry.

Do note that some of the times all the method tried can't work because lenskart is using external marketing campaigns to penetrate the userbase. Which makes them avoid issues of "opt in and opt out". So your only option left at the end is using blocking the number. If you have enabled the partial DND then that can be also be used to block the number.

Type LENS and send it to 567678. It will cost you 3 Rupees.