Vodafone India — Missed Calls from Foreign Numbers repetitively

Address:

Mumbai City, Maharashtra

I'm getting missed call from foreign numbers since last 2 days, but today when i called unknowingly vodafone charged me Rs. 45 for just 4-5 seconds. I accept that i shouldn't have called on that number but my question is that why foreigner will call me repetitively?? and who is benefited ultimately from this entire scene (i.e. malpractice) vodafone only.