AVIS - Overcharge for car rental

Kindly assist with the email i sent to AVIS 2 weeks ago (see below), and getting no assistance: I have the rental agreement and the proof from them that they overcharged me; My contact ********** . My rental agreement number E ********** 36

Good day, i need some assistance with my rental agreement. I was over charged for the following - i rented a car for 2 days with 400 free km and returned it with +- 380km ( But they erroneously charged me for additional Km which they admitted) - They charged me for an extra day, but i returned the car at 8am and not 5pm as they claimed on the invoice (They have acknowledged their mistake) - I was supposed to get my deposit back within 6 days (I am still waiting) Avis in Secunda said they will send an email to customer service and copy me. I still don't have that email. Please assist in resolving this quickly, i need money urgently. Regards, Thabo