synched photos won't delete from iphone5

I have followed directions on how to delete synched photos (from iTunes to my iphone 5) but to no avail. I used these directions:

To delete synced photos and videos from your device

1. In iTunes, click the Device button in the upper right corner. (If viewing the iTunes Store, click the Library button in the upper-right corner first.)
2. Click the Photos tab in the resulting window.
3. Choose "Selected albums" and deselect the albums or collections you want to delete.
   Note: To delete all synced photos, deselect "Sync Photos from" and, when asked, click "Remove photos."
4. Click Apply.

Still, the photos refuse to be deleted. Argh! Any suggestions? I have rebooted my computer and my phone both. No luck. Many thanks!

--Amy