not sure if this phone number actually starts with 515 but i got a call from it without the area code and i have a 515 number. I couldn't really understand the recording but it said my credit card was locked. It said kesser or kessler and I've never heard of them.
I got it after purchasing something on ebay/paypal (not sure if there is a corilation)

same thing happened to me.  No area code, but I have a 605 area code.  Sounds like fraud to me.

Same thing here no area code, but i'm in 515 also.

I received a call from this number, sans area code, claiming my Master Card account has been closed and to reset they needed my 16 digit credit card number.  Since I DON'T HAVE A MC CREDIT CARD I IMMEDIATELY SUSPECTED FRAUD. I have reported this to the consumer fraud division in hopes they can determine who is perpetrating this fraud!  Do not fall for this type of crap!

This number called me twice with same MO. No area code. Said my MasterCard had been locked. I'm also a 515. Sounds like a fishing scam to me.