Never receive deposit back

This is the worst service that I have ever experienced. I have returned the car on the 30th of October 2021 and I still (17 December 2021) have not received my deposit back, the consultant kept telling me that they refunded me the 11th of November, I even sent my bank statements to prove that I have not received anything, but they do not get back to me at all. They keep saying they will contact me, but never do. I have sent multiple emails, today I called them for 16th time and they keep putting me on hold and then the line cuts. They are not even willing to send me a bank proof of payment. I have yet to speak to anyone that can help me. Secondly, I initially booked a VW Vivo , but received a Nissan Starlet. I am absolutely fed-up.