NOT PAYING BACK DEPOSIT

About a month ago, my wife started looking at a vehicle to purchase from Mercedes-Benz Wonderboom. after a lot of paperwork and days passing and keeping us on hold about the vehicle purchase after we paid a R50000.00 deposit, they eventually told us that we don't qualify to buy a vehicle. but strange enough on that same day another car salesman from another vehicle branch phoned me a said that I can have been approved and that I can go sign the contact and get the vehicle which I did. Now Mercedes-Benz Wonderboom has to pay back my deposit as I did not purchase the vehicle from them, but its been almost a week and I'm still waiting. they are very quickly to take your money but when it comes to paying you back they take their time and have excuses the whole time. this is unacceptable and I will never purchase a vehicle from Mercedes Benz.