Try to find anything you can, as insignificant as it may seem that is close to the June 15th date, then get someone to write you an affidavit to go along with that piece of evidence.
Download
http://www.mediafire.com/view/?j1573ii9ly6qx2r
__________________
Self filed AOS │Apps Received By USCIS - 3/18/19
│Biometrics Done - 4/11/19
Interview Scheduled - 4/24/19│Interview Date - 5/31/19│AOS Approval - 5/31/19
Permanent Resident Card Received - 6/8/19