Bad service to clients

I went to KFC Wilropark around 13h22 to buy lunch. I ordered the Summer Lunch Box special which comes with a burger. I normally ask them to change the sauce to the white sauce and never did they complain about it. Today they tell me that I have to pay R 1.00 extra to get the sauce and this comes from management. I asked the lady Maria why do I need to pay as they are keeping the other sauce and whenever we buy from them they never give us our 10c or 20c change but that doesn't count. We do buy from this KFC outlet often as we stay just down the road from them. She wanted to give me the sauce but I took my money and left as I feel that KFC Wilroparks owners are greedy for asking customers to pay for extra sauce and it's just another way to make more money. I will not buy from you again...