It was without a doubt the worst service in a restaurant I ' ve ever had . And I was wound up and tired . I 'd missed a call from Nicole , and because everything was late , I called her right away to find out she 'd had a bad day too . There 's now a cold pit of despair in my stomach , or maybe that 's just dinner .

Give answer the following question using evidence from the above passage: What caused the narrator unhappiness at the restaurant ?
They disliked the waiters .