Im True?

I have always been taught that a true friend is someone who is there for you when times are both good or bad. A true friend will tell you things, not in the interest of your feelings, but in the interest in helping you whether it hurts your feelings or not. So what do you do when you continue to help someone or a group of people who consistently go down a path of negativity. A true friend would worn them, give them advice, or even come out of their own pockets to help financially, right? The bible says you should spread the word and help people everywhere you go, not to look down on them or consider yourself as "better", but to help where you can. But the bible also says that if the person does not accept your help you should wash your hands off the matter, shake the dust from your feet, and move along to the next. Now my question to you is, in a situation where a person you have warned, given advice to, and even come out of your pocket to help financially continues down the path of negativity at what point do you wash your hands and shake the dust from your feet? Or is that not being a true friend?