buy before you using toilet

I was on my way home and my kid wanted to use the bathroom I thought of KFC as we buy regularly,but havent got to a point where I need to use the bathroom, to my suprise  I was told that I need to buy show the slip then they will let me use the bathroom ,A big brand company like KFC DISAPPOINTING.(I explained that it was for my son)the 2 cashiers where not hearing any of that they just repeated ( YOU HAVE TO BUY FIRST).