The call I receive says:
"We recently mailed you a postcard to activate your extended warranty coverage. This courtesy call is your final notice that your vehicle will be removed..."
The call comes from a telemarketing company who I found to be working with Auto One (they claim to be based in Irvine, CA)
Their number is 1-800-930-2791
They will tell you something different each time you call - just call back if you don't like what one person tells you.
-I'd recommend speaking authoritatively and letting them know you have called before, putting your number on the national do not call registry, and setting up an autodialer to call their 800 number every 20 seconds