Is getting assignment help right for students?

I am a student and am given an assignment in my college. To get my assignment done I require help, looking for the best assignment help that is 24/7 available and easily accessible for urgent reviews and revisions. It will be appreciated if I get more than two suggestions for the assignment to help service providers so that I have options. I was wondering if generally, it is ethical and permissible for the students to get help in getting their assignment completion. Because somehow teachers could reject the submission if they get to know. Kindly guide me if it is right.