Struggling to get holding deposit back

I rented a bakkie from the company on 23 February 2022. I collected it at Cape Town International Airport and had to put down a deposit of R4,000 which according to the agent who helped me, would be returned to me 2 weeks after I return the bakkie. I returned the bakkie at Oliver Tambo rental office on 27 February 2022. No problems were noted upon inspection at the return. I called them on 23 March 2022 to enquire about the return of deposit. This was 10 days after the 2 weeks lapse period which the agent mentioned. The response I got from the "holding deposit" department was that they would escalate the matter and I should have my money after 14 days. Today is 15 days and still no R4,000 paid back to me. It surely is nice to make interest off the public's money!! I will not use Thrifty again, neither promote them to other people!!