Who called from 2313547554

Received 2 calls about 4 days apart.  Shows as from Coral, MI.  No message left either time.  I did not return calls.

Received the following:
1/12/15 at 9:47 am
1/9/15 at 12:38 PM
1/8/15 at 3:50 PM
1/6/15 at 5:07 PM
No messages left at any time. I did not return the calls, nor did I answer.

I believe it might be On-Star following up on the free 3-month subscription you get with a new vehicle.