I'm sure you just made a silly mistake (or not), but it is JUNE 15, and not july 15. But I would try
I would try to get the document that has the date closest to JUNE 15 as possible. Something from before and something after. After that , I would try to get some affidavits, but keep in mind that affidavits are not enough, you need something in writing that has a date as close to june 15 as possible.