Don't Trust Martin Jooste and Brain...Poor after sale service

Martin Jooste the sales manager and Sales agent Brain Tshabalala, These guys don't want to do my license and registration of the disc and plates yet I paid for it. They said I must drive without it or take a refund, how can I take a refund, the car was on finance, its the banks money, and they charging interest on it, if he refunds the cash amount, I'm still left with a loan that has interest for the next 5years... Please help get this sorted... Secondly They sold me a car with a oil change notification showing on dash, I've been begging them to help but they just not bothered