I have had the same issues as Margypops...almost to the letter and I know that it can be very frustrating. I have asked my health care provider to have my daughter referred to a Pediatric Urologist as well as a Peadiatrician. We have started a "Potty Chart". I placed it on the back of the bathroom door. She helped me colour it and we went to the store and she picked out a few different types of stickers that she really liked. Everytime she goes pee on her own or stays dry for a period of time....she gets a sticker. Every 10 stickers she gets we go to the store and she gets a small treat. Nothing big just a little positive reinforcement. I know it can seem really tough not to get upset...but hang in there.
I don't think she is choosing to pee herself. Like Margypops said - concequencing this behaviour could make it worse. Have you looked into medical issues prior to being short and disciplining her??? Perhaps she needs some patty training again...with some rewards or something. I think you should stop concequencing her immediately though. You have no idea if she has control over this or not. Imagine her own embarrassment when she will pee herself in front of her peers. This could lead to a more seriusl problem where her friends will make fun of her and she can't trust that her own parent will be supportive of this behaviour and there could be further harm done to your relationship with your daughter. I would seek medical attn. immediately.
First of all this isnt a problem where you punish as that makes her anxious and the problem could get worse, have you asked the Doctor to check if she has a urine infection, sometimes children do not wipe too well . Sometimes you have to start again, take a step back, put a cover under the sheet and then its a sheet to wash, but make no issue of it, I do know the more you react the more she will react , out of anxiety that she is going to do it.(if you get my drift) Make less of it ,a trip to the Doc would be a good idea , he will advise you.