Bad services

My insurance book me a group H car with avis from day 1 can't give me what I need to have After wait for 3days they give me a car that is service due Now they want me to take the car for service If they replace it I need to pay for the fuel They replaced the car but bring me a group F but over the phone they say it is a groupH So now I pay my insurance for group H but I get a cheaper Car Do you think is fair otherwise this insurance must say to me why they sell something to me they can't provide Or change rental companies for me