I attend a hobby class every Thursday morning 10am to 12. The group is run by a very nice lady and we have all become friends. It's 5 pounds to attend each week which covers tea/coffee, rental of the hall and you can purchase supplies of the teacher. Now the teacher is a on call TA at a preschool and as she gets paid more for this job occasionally we turn up and there's no one to run the class. Lately this has been happening more which is disappointing. Last week I received a text message from the teacher asking if I could set up the class, call around to her house pick up supplies, make tea/ coffees, tidy up and return supplies to her house while she was at work. I agreed as I enjoy the class. The next week the teacher came and asked if I had collected the fee which I had not. She then asked everyone to pay double for last week and this week including me. I was abit annoyed as it would have been good manners to not charge me as I actually ran the class. So my aibu question is it ok to agree to run a class not turn up when you have a better offer and expect people to pay