Here is a copy/paste of USCIS’s announcement of returned H1bs.
USCIS announced on July 14, 2015, that it completed processing the return of fiscal year 2016 H-1B cap-subject petitions that were not selected in our computer-generated random selection process.
USCIS previously announced on May 4, 2015, that it completed data entry of all selected cap-subject petitions.
If you submitted an H-1B cap-subject petition between April 1 and April 7, 2015 and have not received a receipt notice or a returned petition by July 20, 2015, you may contact USCIS.