Tempest Car Hire - Questionable Business Ethics

Once you've returned the rental vehicle and received the final invoice indicating that they owe you R5595 as a return on the deposit that was paid, good luck in getting the money back. Numerous mails have sent, the last one not even being answered. It's now been 2 weeks since I returned the vehicle. This is an additional income stream for them keeping customers' deposits and delaying the reimbur*****t as long as possible. Shocking business model. I'll give them a wide berth in future