Cash back

I recently bought a car from toyota tzaneen and the service was excellent there.i am even happy with the car. But something happened that I am still failing to understand. My sales person told me that Toyota will send some money to my account,and with that money i should transfer to the person who refferred me to him. Then before i got the money the guy called me to ask if i got the money and i asked him if its possible for me to ask Toyota to deposit the money to his account and he was very aggressive and said he will just ask them to cancel the transfer and i said its fine he can do that. The money came in and unfortunately I didn't get a notification from my bank and it took me a week to notice that the money was in. I transfered the money to the person who reffered me. By later became unsettled and wanted to understand well why the money was paid to me. I called Toyota accounts and asked them inderectly and they said the money was my cash back. Then i called the sales person and he said he will return back the money. My husband called him and told him he will report the matter and he told my husband that will cost him his job. Today i called accounts again and they said they will ask the manager to call me. The manager explained the same thing as the sales person. My question now is, i want to know if anyone has ever came across such experience where you have to be sent money to pay commission to people who refere you. And again why does accounts says its cash back. What is cash back?