Who called from 3137490013

Received a call...caller id shows 313-749-0013 Intl Call???  I answered and a recording stating they were from COOP Services Credit Union and my VISA has been suspended and to press 1 to activate it again.  Sounds like a scam to me.  I hung up, but it kinda scares me to think they may be gaining information from others and my self by making these automated calls.

Received a call just before noon (called ID showed "Intl Call"). I let my answering machine take it. They hung up halfway through the message.

called me twice today. do not recognize the number even if its supposedly from my area code.  left a message but it was muffled. almost like the phone went on in someone's  pocket

BUT

it was then followed by three rapid calls that showed up as Unknown in the caller id. no message.  called back even after i rejected one of them

this number keeps calling me..just recently 5 times in the past half an hour..its getting really annoying

Whoever this is they are callingmy house every half hour or so all day. I answer it and nobody is there. I tried calling it back and it says the number is not in service. I am gonna lose my mind!!!!!!