KFC thabong Welkom

KFC thabong Welkom. I went there before 6pm to buy 10 pieces of KFC chicken, I asked how much was it the lady at the drive through said it was R180.00 so went to pay for my order with R200.00 I got back R20.00 change I then asked for a slip to check my order then I was told I will get the slip at the next window when they give me my order. I then proceeded to the next window I was only given the order not my slip and they said to me I should go to the parking lot they will bring my slip. The lady gave me wrong slip twice 15munites and when I check the slip it was a wrong slip again so according to the slip my change should be R28.00. I saw so many drive through cars not been given a slip those who pay cash. So I'm asking myself why did I receive a wrong slip for the second time either they did not till my purchase that's why there's no record of my order and de*****ing KFC thabong or they robbing customers.