I think you need to go back and check if you can use the funds for 2015 expense through June, or if it is really only for 2014 expenses. It seems like some of the responses are assuming you have til June 2015 to incur the expenses. I think you said otherwise.
But having 6 extra months just to submit seems excessive. I would call the provider and ask, and do it soon. I could see the plan having an early 2015 date to spend (say, 3/31/15), and a slightly later date to submit (6/30/15?)
My plan has a 3/15/15 spend date and a 3/31/15 submit date for FSA funds set aside in 2014.
The plan rules are the plan rules, it doesn't matter what some person in HR told you.
If it is only for 2014, can you go back and find stuff that you could claim? Some plans allow mileage to Dr. appointments, too. If you purchased any first aid supplies, sunscreen, etc, see if you can find those receipts and submit them. Any copays?
If you still have time to spend it, it's easy to hit $400. Just go to drugstore.com and stock up on FSA eligible stuff.