Anyone know how to stop these messages?

I keep on getting these bsnl messages from like 3 different numbers atleast 15 times a day. I just put in an old bsnl sim from a long time ago into my main phone where the sim was sitting inactive for 3 years, and I started getting flooded by these messages after putting the sim in.

I keep on getting these bsnl messages from like 3 different numbers atleast 15 times a day. I just put in an old bsnl sim from a long time ago into my main phone where the sim was sitting inactive for 3 years, and I started getting flooded by these messages after putting the sim in.