What a loser. And I feel so sorry for you and your DD being continually let down by this bum.
You should broadcast what he's done to his family. His habit will thrive on the secrecy and he'll just carry on, wreaking destruction wherever he goes.
Contact his sister. Not by text. Call her so that there can be no misunderstanding.
Gather together some Gamblers Anonymous literature and post it to your ex, if only for your DD's sake.
And never, ever, ever allow him to raise your expectations again. He will only let you down especially when it comes to money.
Thank goodness your DD has you to make sure she's well looked after and financially sound.