I'm so irked for you! Gah! I would be sending a text that states: "This morning I was caught off guard by your comment about picking up ____ after 5pm. As you will remember in the contract that you signed that I close at precisely 4:30pm as I have family commitments after that time. Also, regarding payment, I can not be flexible in moving around when fees are due. Please arrive tomorrow with full fees for the next two weeks in order to maintain your daycare space. Thank you for your cooperation." Send it!!