Cheap Car Rentals in Østerbro, Copenhagen from $5

A) First I booked a medium car for 1 day by phone. The booking nummer was 2073-8471-DK-5. Avis would have charge us for round 7271, or 1065 USD !!!!! Just before accepting the paiement I fortunately cancelled the booking.Then I made the booking via KAYAK for 69 UDS !!! . How is it possible to have such a difference in the rate 14 times more. B) Then I made the booking via KAYAK for 69 UDS !!! Before taking over the car I phoned AVIS office to tell them we could be 15 minutes to late according pick-up time and also to confirm the booking. We show up at the airport, and unfortunately the car was booked in the city. I'm so disapointed that the assistant didn't told me I have to go to the city. C) At the desk the told us our credit card is not accepted. Big discussion, and then it was finally OK. All of these points for 1 booking. Very poor service. The car was dirty (2 bottles under the seat, snack bar packaging in the pockets)... The naviation system was on "Do not use motorways", we spend long time to find out how to do to take it off. Best regards, Romain