Usually it allows you to select the backup file :S as in you just go to the place where you stored the backup file you made via iTunes. Even on HTC's site the official method is as
Use iTunes 9.0 or later to create your iPhone backup to your computer
Connect your HTC phone to your computer
Download and open HTC Sync Manager on your computer
Click More > iPhone Transfer and click Get Started
Select the iPhone backup file and click OK
Select the types of content from your iPhone you want to transfer
Click Start and you’re ready!
Anyhow, try creating a fresh backup file from your iPhone and see if that helps. If not, go to iTunes and see whether there are any backup files there or not
Contact management on Android is a bit more involved (or so it seems to me). I realize I'm a newbie at the OS (only had my M8 2 weeks), so I'm trying to understand how it handles all the contact info. At one point I had 4 contact databases on the M8. Google, iCloud version, AT&T version, and the phone's version.
Have gotten back to only having 2 contact databases now (Google and iCloud's), after rooting, installing SU, and S-OFF, as well as flashing the stock Google Play Edition ROM. I'm sure it wasn't necessary to do all that, but I like to play with the UI a lot. I'm understanding just a bit more about the OS now But still reading/trying/learning a lot.