Customer right violation

I am so disappointed at McDonald’s as a brand. I went to McDonald’s commissioner street Johannesburg cbd.I went straight to the kiosk machine to order something but I was so pressed I needed to use the toilet so bad.I than decided to leave the kiosk machine and went to use the restroom but the door was locked,I then went to the lady working there asking for a key so I can use the restroom to my surprised I was told to buy first before using the restroom.anyway I went back to the kiosk machine and just ordered anything coz it hard to make a choice under pressure as soon as I was able to use the restroom I was actually mad angry because I don’t like what I ordered so if this is how you treat customers it fine I am sure you don’t care about losing just one customer but I am disappointed and I feel my right to a restroom was violated as I feel it against the law to do that .it doesn’t matter whether you u are trying to block outsiders to just use the toilet without buying but you have violated my right.