When I ordered a chicken sangwich with extra mayo, and took a bite to find no mayo whatsoever, I politely told you that my order was messed up.
You, in turn, became a snarky cunymuffin and told me 'if I wanted mayo on my damn sandwich, I could find the condiments and put the mayo on my fucking self'.
Not so much love,
The customer chick who was glad she had friends for witnesses and your manager was there at the time so she could watch you get fired.