Would you be annoyed by what the restaurant did?

I went out to eat tonight and my dish comes with one side. The side I wanted is a pricier side than most, $3.99, so the waitress told me there is an “upcharge” and I said that’s fine.

We ate, and then when the bill came the side was charged at the full $3.99 for the side. I asked her about it, and she said that’s what the side cost. I thought maybe she had charged me incorrectly, but no, she said that side is more expensive. I said I know, but why am I paying the full price?

She wasn’t getting it.

I said, “name me a side that’s free with the meal.” She said, “a baked potato.” I said, “so if I had ordered a baked potato, then I would get that with my meal, and I can order the side I did get in addition for $3.99?” She said, “yes.” I swear she still didn’t get it. She just started saying it’s not her rules, stupid, ridiculous, babble, something or other. Can it be no one else complains about this? I told her I’ll take my baked potato to go.

Am I wrong?