Unsatisfactory experience

Last week I rented a car with Avis and I requested additional 700 km to be added because I was traveling very far and then then the normal standard 200 km a day would not have been sufficient so for me not to pay a lot of additional kilometers when I bring back the car hence why I requested this additional kilometers to be added to my surprise when I I received my invoice I was never given the additional kilometers and hence was charged additional kilometers that I traveled I was very unhappy about this whole situation and to add to salt to the wounds they never actually wanted to investigate first before they actually resolved the query on the invoice and I was told that they will refer back my query to the branch and up to today I have not received an email or a phone call just to hear what my issue is and then on top of that all I know is that when Avis that they care about the people not the cars well in this instance they are contracting themselves because all they care about is just the money and not the people so what I expected actually was for this query to be finalized before the invoice was completed