Sellers that don't ship?

I purchased an item and the seller marked it as shipped the same day but there was no movement in the tracking for over a week. So I sent her a message asking when it will be shipped.

She apologized and said she was on vacation and will ship it Friday 10/25. I'm going to give it until Wednesday and if there is still no movement I will cancel.

My question is, is there a way to leave a bad review if I cancel? I'm so sick of sellers doing this with no repercussions