Cashier was refusing to give me slip or paper for my purchase

I went at Street Nonkqubela mall Khayelitsha yesterday around 3pm to buy myself washing basket and towel,and there was loadshedding ,this lady said to me she wont give me a slip due to that,understandebly enough,but my question to her was aren't I suppose to get anything like piece that shows that i was there to purchase and they seemed not happy about that but they ended writing down what i bought on paper and what shook me the most is the level of unprofessionalism and other one was sitting down with her phone