No Deposit refund after more than 4 weeks

While visiting South Africa in Feb/Mar 2022, we booked 3 vehicles consecutively in Cape Town, East London and Johannesburg, over a period of almost 4 weeks. In each case we paid a R2000 deposit. 4 weeks since the end of the last rental, and 4 e-mails to customercare, we still have not received any refund. Due to a series of administrative errors on their side, were were also incorrectly charged an extra day's rental, retrospectively, which also has not been refunded. Strange that they were quick to charge the extra, but not refund the deposits. Today, the response to my latest e-mail to Customer Care, quoting their ticket number, asked me to repeat all the details for the 3rd time! Absolute incompetence! I certainly won't be going anywhere near them again, no matter how desperate I am!