Air tel
Blank Calls and SMS

Dear Team,

I Have been receiving blank calls from the following numbers followed by an SMS saying

a) "I am frid what are you doing? reply me,?

b) :Who are you da"?

Nos from which the messages/ Blank calls are being received

a) 919789684005

b) 919944337516

c) 918056837267

My number is 99522 10333

Inform how can this be stopped and details of the mischievours