Nightmare Online order pricing

I placed my order Online yesterday like I always do before with no hassles. I placed 1/4 chicken that goes with a side. It was R53, and it gave me an option to either pay in-store or use my debit card. Like always I chose pay with debit card. And I received a confirmation SMS for the completion of my order. I went to the store Nando's Jabulani Mall at about 16:30 to collect my order, that's when the nightmare begins. I showed the lady the SMS on my phone with the order number and I told her I have already paid. She checked the order and came back to me saying that I haven't paid. I insisted that I have paid and I had to logged in to my banking app and showed her that R53 has been deducted from my account to Nando's. She asked the lady who was on the counter and she said there is an outstanding amount of R2 that was not paid and I HAVE to pay for it. I was astonished. I asked how is that possible and they said the price has gone up in-store not in the app. I told them I don't have any cash on my I only have my card and I was not going to swipe R2 from my card because of another additional bank charges that will occur. She told me there is nothing she can do because she was not the one in-charge of the pricing. I ask her to call their head office so that I can speak to them, she reckons that they won't help me either. I asked her to call whoever that I can talk to regarding this issue, she went and call the other gentleman, I suppose he was the management. Another disaster. He insisted that I should swipe my card so that I can pay the outstanding balance. I ask if I was the one who was at fault or not, he said no and he was also not responsible for the pricing on the app. I ask if I was the one whose supposed to pay for the mistake that was not created by me but by them, I even emphasize my statement ( by them I don't mean him as an individual but the establishment as a whole). He said to me he was going to help me if I came with the right approach. Was I supposed to beg for them to override the price on the till to match that price that I saw and paid? I was puzzled by his statement because I thought serving with a smile was their part of the job not mine as a customer. He also said if I was a regular customer I was supposed to know this. I've been buying using online purchase for the longest time without having any problems except yesterday, you can check my invoices. I spent almost 30 minutes of my time going back and forth about a mere R2. I eventually have up I I said to him swipe my card but I'll make a review on hello Peter, that's when he said it's fine I can take the order and leave. What was hard to do that on the first place because it was not my fault. If it was R55 by the time I made a purchase Online I was going to pay that but it didn't. Online purchase should be efficient.I felt like I was undermined because I was wearing my security uniform. I couldn't enjoyed my regular meal because of the way they made me feel My cellphone number is 0676089019