I WANT MY MONEY BACK!!!!

On January 12 2024, I bought a car part, deposited the requested amount. The part was sent by couriers to me within 3 working day, only to find that it was an incorrect one. I had to re-turn it via Paxi on the 1 February to Randburg. They only collected it on 12 February. I was then promised to be refunded but up until today They haven't. I keep asking the person who helped me about my refund, but I am being told the manager has not processed the refund, yet it is approved, since February 12th. And I am being told that there is no money to pay me back. How on earth is that my problem? All I want is my money, no excuses!