It's a matter of principle

On Sunday 7 Feb 2016 at about 10/11 in the morning we went to Wimpy in Volksrust. I ordered a breakfast item that comes with pork bangers and so did a friend of mine and since I do not like these and my friend doesn't eat pork we asked our waiter if was it possible to substitute these for lamb sausages. She said yes and wrote down the orders. For some reason when the bill for our table came we were charged extra for the lamb sausages. When we asked our waiter about this she simply said, \there are no exchanges.\" I found it unacceptable that she explained this to us after the fact. She also made it seem like our fault for not knowing Wimpy rules as if we work there or eat there all the time. "