Sounds like a call to Enterprise is in order.
When I flew in I had to take a airport shuttle to the garage they were at but very easy. They charged 80% up front I believe then the rest is billed upon return. They gave me a itemized receipt that day and when I returned the car as long as there wasn't any damage and fuel is back in same place that's all you owe. Pretty upfront with them. They did push me to upgrade pretty hard but otherwise of all I've used they were the best.
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