Pathetic service

I hired a car for the month of June however only needed it until the 12th so I returned it to the OR Tambo branch at 10 on the 13th of June. I sent 3 emails to customer services asking what the procedure was when returning a car earlier. I am still waiting for the courtesy of a reply. Please advise how long I need to wait for refund for the days not used as well as deposit. Not even bothering to send an email as I won`t get any reply.