I’m a little surprised Hertz didn’t contact you sooner. What was mentioned by corporate in the call? Did they extend your contract?
I’ll also echo everything that has been mentioned previously in the comments. Having a Jeep might be the least of your troubles right now.
I’d return the car as soon as possible or you could be facing some serious legal trouble, especially if the car is marked as stolen. Status with Hertz won’t help you there.
Good luck!