Disabled toilet nightmare

I went into the shop on Monday cos I had 20 Rand notes and asked the cashier to give me change so that I can use the toilet. Then I asked for her permission to use the disabled toilet as I have a multiple knee surgery that left me partially disabled, I walk on crutches and use leg rom. So since I was in a car for too long I removed my leg rom and limped into your fuel station from the parking to the toilet it's not far. She politely told me to go to the toilet and inform the staff lady who went in to let me use it. Yoh I met a woman who was disgusted by my side especially when I mentioned I am partially disabled...the way I explained to that lady why I needed to use the toilet it was like she needed medical report. The look in her eyes was that of a woman who doesn't care if I peed on myself or not. Why have a disabled toilet if we are not allowed to use it as customers. Yoh that lady is very rude. I remember her saying'why can't u use a normal toilet BCOS u still going to bend your knee in a disabled toilet' mind u the disabled toilet has a steel bar where we balance ourselves when standing up. After using the toilet I went back in to inform the cashier as to how a woman mistreated another woman only BCOS of my mobility