The will to quit gambling is always being beaten by addiction. No matter how you wanted to quit in gambling, if you really get addicted, you will return even if you have stopped for how many days, weeks, months, years. There is a time that you will go back to your habit.
If the person who is gambler and wants to leave gambling for good, he himself would start hating gambling by his heart after that he would be able to leave gambling because he is the person who is addicted and he wants a cure and as it is a common sense thing that if the patient would like to be cured, only then he would be cured and beside this, nothing else can be done.