Originally Posted by
Often1
You changed the reservation, so you pay the rate for the new reservation. If higher, you pay more. If lower, you pay less (or get a refund for the difference). Not just Avis, but other car rental companies too.
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This is incorrect. After they wanted to charge me more for a one day shorter reservation, I changed to a smaller car which was a $100 cheaper fare. The now say that my prepaid rate was a voucher for up to the amount I originally paid, and I did not receive the difference back.