Most people who keep doing the same fails over and over again, expressing a 'desire' to change, are most likely caught in a state of immature rebellion.
It becomes a case of people trying to get the person to do the necessary things to change; but, refusing to do so is like getting back at your parents who made you clean your room.
While it was a healthy thing to keep a neat environment, you resist positive changes as an adult to prove the lie that you have no one to answer to but yourself. At the end of the day you have to answer/account to God for everything you rebel against.
Overeating/overspending are excellent examples of rebellion gone amuck. As long as the rebellion continues, satan wins; and of course the person in rebellion loses.
Peace.