important text messages lost after iOS update, cannot restore from iTunes backup, HELP!

I'm getting ready to get a MacBook Pro but right now I'm using a Windows XP machine. I updated my iPhone 5C just before iOS 9 came out, I think the version is 8.4.1. I had some important text messages saved in my phone which I need for court. I have them in print but they need them on my phone as well. I did an iTunes backup before the update. After I updated, all of my text messages were there except all but one of the ones I need for court! The important ones had been whiped from my phone by the update for whatever reason. When I hooked my phone up to my computer, I got an error message saying my version of iTunes was not compatible with the version of iOS I'm using. Apple Accessibility support told me that there is no later version of iTunes for Windows XP than 11 which is what I have. Now I'm stuck with an iTunes backup that is completely useless to me unless there is some other way to restore it. I did not have iCloud backup set up on my phone at the time of the update because I thought that backing it up with iTunes was enough. I don't even know if an iTunes backup that was done in iTunes 11 for Windows can be restored on a Mac, and Apple Accessibility support couldn't tell me either. Lesson learned, don't use iTunes for anything but transferring music and apps. USE iCLOUD BACKUP! What do I do now with this iTunes backup I can't restore?

Forum: 

#1 You need a newer OS

While I haven't experienced this issue myself, it sounds to me like the only solution is to get access to a computer with a newer OS, capable of running a newer version of iTunes. Transfer your backup to that computer, and restore from there.