CELPIP Speaking Task 6 asks you to respond to a sensitive or uncomfortable situation. The key is to stay polite, explain your decision, and offer a reasonable solution.
Hi, I’m really sorry, but I need to talk to you about this weekend. I know I promised to help you move on Saturday, but my manager has just asked me to work because another staff member is sick. I feel bad because I know you were counting on me. I may not be able to come in the morning, but I can still help you in the evening after work. Another option is that I can help you pack on Friday night so the moving process becomes easier. I hope you understand the situation. I really do want to help, and I’ll do my best to make up for it.