Money not returned to me

On the 15th of December 2014 I hired a car from Avis @ OR Tambo International Airport and I returned it in Port Elizabeth on the 19th 2014.I went to Walmer Park Branch to sign a dispute form on the same day that i returned the Vehicle.7 days Later I went to Greenacres Branch they are too let me to sighn that dispute form,7 days after I went to Greenacres I then went to Kenako Mall as usally I sighned that form .They said they gonna call me after 3 working days which I'm still waiting for that call till now.This past Saturday I went back to Kenako Branch They said they gonna call me after 7 working days,Its been 2 Months now ever I'm waiting for my money.I wonder how must I wait nw? All i want is my money and they can close that account for all I care.