I used Avis due to certificates. After calling all Avis' from north Phx to sky harbor circle to get an associate that didn't have an attitude. Avis customer service & the Avis counter associate told me to use the gift certificates when returning the car & refused to take them when picking up the car. As I return the rental the Avis counter associate told me I need to use them when picking up the rental. After arguing & being told I'm cussing when I didn't. I now have to call Avis customer service to "see" what they can do. Avis is the absolute worst rental company I have ever dealt with. I for that matter. The counter associate wasn't helping & acted as if he didn't care & the supervisor was rude & assuming. If the review would submit won't negative stars I would put that instead of one star. NEVER USE AVIS!