Refund request

I've make a booking on the 22/12/2020 for a vehicle from the 28/12/2020 till the 3/01/2020 and made a payment od R4300.00 immediately. They promised to deliver the vehicle on the 27th at 17:45 but they never did till to date, i've been trying to call them with no luck, I sent them ato whatsapp message and they only responded once saying they double booked my vehicle & they will refund me but its been over 48hrs with no refund or no contact from them.

Till to date they still ignoring my whatsapp messages and they always not answering their calls.