Sorry, but once your soles are gone, there's nothing worth doing. Maybe covering the hole until it widens a bit more. But you'll have little grip or support. I like to patch it up from the inside with some duct tape, but only to make it last a little longer as the hole eats through the rubber. Consider sanding your griptape a bit. Vulc shoes are usually more grippy, and the sensitivity might help you learn not to drag your soles so much.