I can't delete photos

I have an iPhone 4S .

I only have 3 gbs of storage left on my iPhone

So I deleted all photos and video from the Photos app on the iPhone.

I emptied all photos from the "Recently Deleted" album.

After visual inspection the photo app / camera roll the iPhone appears empty.

I can't find any photos or videos but I did not gain any storage space.

I reset the iPhone (home key and sleep wake) but I did not gain any storage space again.

I did NOT reset to factory setting because I don't want to lose my data.

I connected the iPhone to my laptop and I opened iPhoto.

Under devices iPhone there are no photos or videos to import.

The iPhone is empty of photos or video according to iPhoto on the Mac

I connected the iPhone to my laptop and I opened Preview.

Nothing there. Empty.

I opened Image Capture.

Nothing there. Empty.

I connected the iPhone to my laptop and I opened iTunes.

According to iTunes there are 512 photos still on my iPhone!

I unchecked Sync Photos. Checked it again. And then unchecked it again.

There was no Apply button only a Sync button. So I clicked the Sync button.

No change. iTune still reads that I have 512 photos on the iPhone.

I checked to see if there were any photos on iCloud. None.

I checked to see if the iCloud settings on the phone were set for photo.

It is not set for photo-iCloud.

Why does my iPhone (thru iTunes) still show that I have 512 photos that

I clearly deleted? Why can't I gain more storage space?

Thanks