DEPOSIT REFUND WOES/STRESS

Can someone please assist. Hired vehicle from port elizabeth airport. Trying to get back deposit of R4000.00. Have spoken to so many people who promise to call back but never do return calls. Sometimes they do not even answer calls for the entire day. Really bad service and customer care. Please DO NOT RENT FROM DOLLAR as you will struggle to get your deposit back. I am at my wits end and dont know what to do.