Upvote:7
You need the I-20 form and the F-1 visa in order to enter the United States as a student.
If the consulate is unable to return your I-20, you must consider it lost and request a replacement form I-20 from the school you plan to attend.
Since this may take some time, you should make every effort to contact the consulate and secure the return of the document. This includes email, phone, even physically returning to the consulate if possible.