Hello,
Regarding the terribly fitting costume for your daughter, often the costumes at dance classes are cheap and poorly made- I agree they are awful. I think by pulling your daughter out of dance you were, unfortunately, punishing no one but your daughter of a fun experience. Could there have been a better, less extreme option? I am not excusing the behavior of the owner, absolutely not. But could you have politely- but firmly- insisted on a larger size, could it have been altered in any way? (my daughters costume showed everything from the side- I did a quick stitch on both sides and it worked great) Anyway, it is in the past. Going forward, I would do just about anything to try to avoid pulling your daughter out of things. It isn't fair to your daughter.
As far as soccer is concerned, I know with our league, it is almost an entirely volunteer association. So, understand it is almost never going to be perfect- also- these people work hard, and are often overworked and underappreciated. So you may want to keep that in mind.
Have you asked for a smaller size from the head of the organization? I would start there. You don't want to pull your daughter from another activity. I would either hem the shirt, request another size for safety reasons, try to switch with a larger child, or tie it up. Since you signed up late- they may not have extras.
See if there is someone else you can meet with to complete the registration immediately. If not, try to handle "no show" woman by saying something like:" I really want to get this taken care of today, where can we meet? I am available at 6 tonight" Or, say something like this:" I am out today, if you leave the registration information on your porch I will swing by and pick it up this afternoon and get it back to you tomorrow to ensure my daughter can participate in next weeks game" I wouldn't even mention the fact that she didn't show up the other day. She knows what she did.... maybe (who knows!) she had a very valid reason. Don't alienate her right off the bat- she may be the person you have to deal with for years especially if your daughter loves soccer. I have learned to grin and bear it with difficult people, sometimes, if it is to benefit my childs experience. My friend says "Go along to get along" and that may apply in this situation. There are difficult people everywhere. How you handle it is up to you, you can't control the bad behavior of others and sometimes it is better to let it go- for your own sanity.
I think the end result should be making your child happy and allowing her to have a fun time. If that means, smiling and putting up with inconsiderate adults sometimes- so be it. It sounds like you are a strong defender of your daughter which is absolutely wonderful!
I truly wish you the best of luck and no rain this weekend!!!