Courses from other institutions and different courses with essentially equivalent content will not suffice. On the student's transcript the course will appear twice, once in each semester during which it was taken. Only the higher and corresponding credit hours will thereafter be counted. The student must file a petition requesting the higher grade be entered in the record. Courses can't be repeated after you graduate.
Some rules are more flexible than others.
Some requirements are established by accrediting bodies, some by the State, some by the University, and some by the College or Department. Some Department requirements are relatively flexible if you can demonstrate that your plan contributes to a comparable degree of academic strength. If you are denied permission to do something, see the Department Chairperson to determine whether there is an alternative route.