Disappointed on Avis car hire

Disappointed on avis car hire. Getting multiple explanations why I cannot get my refund and all they are Saying is different from what I was told on the day I got the car from them. They are explaining the rental contract totally different from the person who Gave me the car. An additional amount of 292 was deducted from my account without anyone from avis contacting me and they did that on a Friday at the end of office hours so that I cannot call and enquire. Turns out on Monday when I enquired they said all that I say was explained to me previously is untrue.. And I kept calling the branch that gave me the car to ask about the refund they said it's in process only to find out m never gonna get any refund.. I paid a waiver for 30 days they said it's standard even when I was taking the car for 20 days so they said I was gonna get a refund for that 10 days when I return the car turns out it's also not true