I've started using wit.ai and they say to come here to ask any questions about issues.
I've ended up with 4 duplicate responses after trying different things. These responses are now conflicting with each other and I can't delete them. Editing them doesn't stop the reported conflict nor does the option to delete them appear.
Wait for some time(because wit takes long time to update the stories) and go to 'Actions' tab. You will find the list of all actions and responses. In this list, there will be a 'Remove' button for unused actions and responses.
It's annoying - I don't know why these changes don't take effect instantly. Usually a few refreshes and a little waiting does the trick for the conflicts, then the deleted actions will appear in your Actions tab like so ready to be removed:
