How can I recut wine bottles that didn't cut right in the first place

You can try scoring them under the first cut. Are you using the hot/cold water shock treatment? Frankly, it would probably be better to toss the bottles and try again with new bottles. I've cut many bottles myself and find that as long as I've created a good score line they will almost always break neatly. Then I just have to do a little sanding and they come out with a nice finish.

If I were you, If the amount is not too large, you could use a grinding machine, if you have one. Or maybe just sand it down to the required size, like Liz Toone suggests. Good luck.

I finally broke down and purchased a Creator's bottle cutter. It's expensive, but well worth the cost if you do a lot of bottles. I now have a better than 90% success rate with my cuts