Bad customer service

My daughter received shoes as a Christmas gift. It was bought on the 5th of December at Tygervalley. When I tried to return it the first week of January (first opportunity after the holidays) I was advised that I cannot return it without a slip. I went through a lot of trouble to get it from my sister and to go back to the store on Friday the 15th. I stay in Malmesbury so I made an effort to drive through as soon as possible. When I tried to return the item and take something of exactly the same value in its place I was advised that the 30 days had expired. I confirmed that I visited the store the week before and then the problem was that I had to get the slip, hence the delay in doing the return. Deka, who presented herself as the store manager, told me that unfortunately that is policy and she could not accommodate me. She was quite firm that there is nothing she could do for me and made no attempt whatsoever to assist sorting our the concern. She turned around and walked away. I assured her that I will take the matter further and she said that I could contact Customer services if I have a problem. I was lost for words for the cold manner in which I was treated.