National General Ins. is what used to be GMAC Insurance.  They (GMAC) are a provider of Recreational Vehicle Insurance thru Good Sam Club.  Maybe they need to check the phone # called.  I have insurance thru them and never had any calls from them. This may be the start of them calling & bugging people.  Believe if it is that they will be getting a piece of my mind.

who called via this number to say payment is due?

I don't have insurance with these people, yet they are claiming I owe them money!

GMAC Insurance Company.