You have your ePub in hand, but it still has mistakes? Not to worry. I will fix it fast and make it right to pass ePub validation check.
Please contact me first and send the messed up ePub so I can get a better idea of how to approach it. Why send me the document beforehand? Because, sad to say, some ePub files are simply BEYOND repair.
If you still have the original Microsoft Word file, I'll gladly do for you, eBook formatting. Please check my eBook Conversion Gig to format your document for eBook.