The I-94 is the record of arrival and departure issued to visiting or transiting persons to the United States except U.S. citizens, returning foreign visitors, foreign visitors with immigrant visas, and most Canadian citizens. Your I-94 must show the immigration status that you entered the US with, and "D/S" which means that you've been entered for the duration of status on your I-20 or DS-2019.
Non-U.S. citizens traveling to the United States may also download the free CBP One mobile app from the Apple App Store or Google Play and complete an electronic I-94 form up to seven days before their trip. The feature provides a more convenient way for travelers to apply for an I-94, review their past travel history, check their I-94 expiration date and obtain proof of their electronic I-94 from their mobile device.
Sometimes the officer reviewing your case will make a mistake. It is your responsibility to check your I-94 for errors and have them corrected. If you spot a mistake, please contact the Deferred Inspections Office at the airport you first entered into the US through. Usually the error can be corrected by email, but sometimes you may need to visit the office at the airport.
Philadelphia Deferred Inspections Office:
Address: Terminal A West 3rd Floor International Arrivals Hall - Philadelphia International Airport
Phone: (215) 863-4247
Email: philadeferredinspections@cbp.dhs.gov