Expect full price for incomplete meal.

We drive from Pretoria North Wolmer to KFC Ninapark due to regular poor service at the Pretoria North KFC, only to be informed "we don't have tamato". On which we asked if it can be replaced with something else like a slice of cheese, the answer is NO, because the cheese cost money. But KFC expects me to pay the full price for an incomplete meal. But KFC can't add something from their side for their incomplete meal? I left disappointed and without food because of the principle.