Bossa Sunningdale overcharges and robs its customers

I have been going to Bossa every Sunday since last year Nov(2022) for their R79 pizza special. In all that time my friends and I (regulars) were never informed of a supposed rule that you can’t share pizzas or you pay full price. We’ve shared pizzas many times in the past and never heard anything. Last night 3 Dec 2023, after we’ve finished the pizza, we’re informed of this rule. It isn’t written anywhere in the menu or on the posters. Not only did we have to pay full price for something they failed to inform us of, but they tried to overcharge us beyond that too. With the full price the bill should’ve come to R720, the first bill they gave us charged us R880. It was only after a long argument that it was amended. Legally we were not even obligated to obide by this supposed rule because it wasn’t communicated anywhere for customers. And we’ve had a few occasions previously where they messed up our bill.