Trying to make a prepaid reservation in the Avis app. I am quoted a rate, get all the way through to the end of Checkout with that rate, and as soon as I click Pay Now, the base rate displayed on the confirmation in the app as well as my email jumps up by about 12%. The prepaid amount charged to my card is correct, but the reservation total has increased, showing a balance due.

Avis Customer Service tells me that the confirmation email can "never be wrong" and that they can only honor the rate if I have a confirmation for it. Asking why they would charge an amount that wasn't the full prepay amount also fell on deaf ears.

My quoted rate is still showing in the app if I go through the reservation process again, so I asked them to cancel the reservation so I can run it through again. The T&Cs displayed on the reservation plainly state: "If you cancel your booking on the same day the reservation is made, no cancellation fee will be applied." The agent tries to tell me this is wrong, and that I will be charged a $50.00 fee. So they open a customer support case and require me to email them their own printed T&Cs from my reservation so I don't get charged. And they ask me to call back in an hour to see if the reservation got cancelled, since their system was "having issues" and couldn't cancel it. I tried rebooking and videotaped the whole thing this time, and the same thing happens again - the base rate jumps after clicking Pay Now.

How do I get Avis to actually honor the rate I booked at?