Have you previewed your book? This is step 6 in the publishing process, and it does not appear until AFTER your book has successfully converted.
If you have not done so, I hope you will do it before you hit the "Publish" button. Just because the file successfully converted does not mean it looks the way you expect it to. Formatting for KDP can be a frustrating, buggy process. $100 - $200 for a well formatted file is well worth it. New KDP authors lose more sales due to bad formatting than for any other reason, IMO. When "Look Inside" appears, and people can check out your book before they buy, what are they going to see?
For a simple novel $200 is definitely on the high end, for sure, though it's certainly not unreasonable. It's too much to pay for many of the "professionals" who do a mediocre, or worse, job pushing buttons in Calibre or something, of course, but for a real professional formatting job, with adequate testing across various reader platforms, $100-200 actually quite a nice deal for the client.
This is of course referring to a full and proper conversion of the entire book. Charging $100-200 just to fix this one error would obviously be quite high.
If you'd like, I'd be happy to take a look at your HTML. I doubt it'd be anything major to correct and get uploading properly.