Contact them near the end of June.
When I was looking for a part time job in retail, I was interviewed then heard nothing after the date they said they would let me know. I thought I didn't get it and couldn't understand why
Anyway I phoned up and their had been a little mix-up and no one had contacted me. I got the job back in Nov 08 and still got it
Always worth checking up, also shows your enthusiasm and interest.
Luke.