Leaks happen! Whether you like it or not we have discussed the inevitability of this happening over and over again. The key is to not let them get you down and instead turn them into a positive thing for your release. Many times when they do you may have already added your record to iTunes but the release may be weeks away with many of your true fans who want to actually pay for your record and support you being alienated by other fans who are just stealing your record. The temptation leads to lost sales and fans being upset.
One way to compensate for this is to get your record up on Bandcamp as fast as you can. What turns this into a positive thing for your careers is instead of many of the sales going through iTunes where you will never be able to get their emails and a smaller profit margin on your record sales. Sending out a message to your fans via email and social networks and directing them to Bandcamp can make this a win-win situation and help grow your fanbase. It is such a winning situation it may help to just plan on doing this in the first place!