Went through a similar situation with DD1. Every morning we would ask her "nappies or undies". She would choose undies and we would explain to her that undies means that she goes to the toilet or the potty. Every morning she would say yes, but the accidents continued. Well I should not say accidents, many were very deliberate. In the end I had had enough, I warned her that if she wee'd on the floor again she would be put into nappies. Well she wee'd on the floor again, a very deliberate one, so I grabbed her, explained what I was doing and put her back in a nappy. She absolutely screamed, I hated doing it, but I felt at that stage I had no choice, rewards, bribery etc just had no effect. Well it had the desired effect, the next day she went to the toilet each time. We still have the odd accident, tends to be if she is very engrossed in something, but at least they are not deliberate any more. Good luck