pick n pay ruthless behavior to customers

Today i went to pick n pay to buy a drink and a chocolate for my wife , this pick n pay is the nearest shop to my house . i had just withdrew money from the ATM machine and went in to purchase goods. when i was paying ,the cash register lady told me that my money has a stain and that they will not take it . they made me look like a fool , i asked for a manager ,she came but couldn't help and she asked another lady to handle the situation. i was treated like a fool at my age and position . a lady by the name of KATEKANI spoke to me like i was a child. i left with the goods and they refused to give me my change of 5 rands . the truth of the matter is that i am planning to take this to Ombudsman a swell.