In a word, no. If you placed into a 300-level course, this puts you far above where 200-level students are, which is why (out of fairness to those who placed into 200-level courses) we generally won't allow 300-level students into 200-level courses.
As your score would satisfy your language requirement, if you do not plan to continue your language study by taking the 300-level course into which you placed, you also qualify to take the Confirmation Exam. Please note you will only be allowed to take the Confirmation Exam once. Please go to the MFLL Confirmation Exam page for more information.