I recently received a call from this unknown number. I recently (several weeks ago) was surfing the enterprise website thinking about renting a car, but never did. A little freaky that they are calling me on my cel phone when I did not execute a transaction with them, so the whole Customer Service and survey thing doesn't sit right. Feels more like a "use-your-debit-card-at-Target" kind of thing.
I rented a car from Enterprise last week, so it could be them doing follow-up. F.Y.I. Enterprise and National are now one in the same rental car company.