This # is filling up my mail box with silence

This number has called me 3 times in the last 24 hours.  A computer voice says "on behalf of Key West Ford 520-3055" and then hangs up on me.  That's literally all it does, nothing else.

When it calls me the line is dead and no one is there. When I call back it says the number you have called is not assigned. What???

June 21, 2012
1/2 dozen calls in past 2 days...line dea when you answer and if you call the number - it doesn't "compute"...weird

June 21, 20121/2 dozen calls in past 2 days...line dea when you answer and if you call the number - it doesn't "compute"...weird

Just received 2 calls from this number today and on the 2nd call there was a message saying there were calling from Mazda. Wanting to remind me of my next service?