Better communication needed . Why wasn't I charged the price I was quoted??

Firstly it was very hard to get in touch with the Avis staff at Kununurra. The 2 phone numbers when I tried to call prior to the trip had messages on them stating that the phone message box was full. This also happened when I arrived at 11am to pick up the car (.When I returned the car the message bank still hadn't been dealt with and there were other frustrated people).Finally I talked to the cafe worker who knew the Avis rep and he called her. She said she was on her way and would be 5 mins.By this time it was 11.30.She was pleasant and apologised but I expect more professional service.