I have come to know that my parents are involved in harām earnings. I have tried to explain it to them but they didn't accept my arguments. I am staying away from my parents for my studies. They send me money for my needs. This puts me into dilemma to recognize whether this money is harām or halāl. What they send might partially or fully contain this harām.
It is a very a cherished act to be alive to the requirements of the Shari`ah. But when it comes to the situation similar to one you are facing one needs to carefully handle the problem. We are required by the Almighty to put such exhortations before others very politely and very wisely. Especially dealing with your parents is a very sensitive matter. You are required by the Almighty to be very polite and respectful to them. And you must not inter into heated arguments nor do you need to break relation with them. You are only required to put your concern in a very befitting manner and constantly pray to the Almighty to guide them to the right path.
As regards the use of the money they send to you and your concern on the nature of their earnings, I would suggest that you need to use it. The concern you feel is very positive but it must not drive you refusing their aid until you are not independent. They have been burdened with the responsibility of extending financial support to you and it is they who will be held accountable for their earning. However, if you feel that your refusal may bring them to quit the Harām means of earning you may do so. But you are not going to be held accountable until you feel the same way and use it out of compulsion. However, feeling easier on being showered by money earned through ignoble means should be avoided.
At last I would reiterate please to keep praying to the Almighty that He lead them to the right path and keep your righteous spirits alive.