Who called from 3604743288

I don't know who is  calling me

8 Calls in 3 days from this number.  They do not leave a message.  I only answered the phone once and there was just silence on the line.

This number keeps calling me non-stop!  7 calls since Monday, not including calls from other numbers just like this one!   Why am I getting this?

7x in one day 8x another day  never leaves message.

5 or 6 times a day for atleast two weeks..... silence when i pick up, voice mail left when i don't, which is just one second of silence..... how do we stop this???