Aircel
Missed calls from unknown numbe

For past 1 month i'm receiving missed calls from so many 12 digit numbers., like 570007337982, 570007337220, 570007337949, 570007337595, 570007337932, 570007337590, 570007337878, 570007337589, 570007337574, 570007337176, 570007337624, 570007337943..

it is irritating me much! i'm receiving atleast 6missed calls from those numbers per day..may i know y they are doing like this?

please tell me the solution.