Hmm...leather will certainly stretch over time from wear, but if they're really painful, you can try stretching them. I'm not to sure how the fabric layer on top will behave though. If it were me, I would take those to a cobbler and ask how the fabric will react to stretching. If the cobbler says it will be fine, you can either have the cobbler stretch them, or you can try a few ways yourself.
- buy a spray can of
leather shoe stretcher, and wear them around the house after spraying.
- do the ol' bag of water in the freezer trick.
http://www.youtube.com/watch?v=qf5mJ7aR2t8&feature=player_embeddedBecause of the style, I fear that if you buy a size larger, you'll just end up slipping out of your shoe. Of course, you can always try slapping a few
heel liners back there if that's the case.
Good luck!