Can you verify the volume size:
From the EC2 Dashboard, select the “Elastic Block Store -> Volumes” menu item.
So on the left on the screen, you'll see Elastic Block Store (it's below Instances, and then Images).
Then choose the volume ID that is show in your screen shot.
You'll see the size of the volume on the bottom of the screen below the volume ID. Verify it's the new size as you specified before.
Let me know what you find.