Here is what happened   1. I have applied for OPT extension in the beginning of June. USCIS rejected my case because I sent an incorrect fee and sent all the documents back to me, but I sent the correct fee (I have the first money order with me)   2. I received the rejection notice on July 4th and Immediately sent all the documents to USCIS with new money order through overnight shipping  on July 5th.    3. They received my application on July 6th and sent a I-797 notice