Avis charge for refeuling after client refeuls and no refunds

Avis, bad bad customer service first of all you contact customer care and tell them they have incorrectly invoiced you for refuelling. Second they ask for pre payment which i have no problem in doing but had to go home earlier and they dont want to refund me in asking customer care hotline why they said it is in our T&C, but when at branch they said it will be refunded back to you. Thirdly they glad to swipe your card and hold deposits for more than two weeks after you have given car back and cant release and noiw it is my problem because I must contact back. If avis sees this you can look at invoice number ***. Today I have to rent another car also pre-paid and will be the last time I ever rent at Avis, *****ing money for refuelling and pre-paid. Regards, Shaun