Sorry to hear this about your paper. If the version posted online isn't a true representation of the original version presented at the conference, I would send a new, correct version of the paper to the editor and the publishing company (e.g. ScienceDirect) and ask that the one online version is replaced with the correct version or completely withdrawn. Last month, my most recent journal article went online, showing my home (instead of institutional) address. One week after requesting both the journal editor and the editorial manager to look into this matter, nothing happened. So, I wrote them both asking that the article is completely withdrawn. The article was immediately taken down, corrected, and then put back online. Happy days! You need to be very firm. Your publications constitute your academic identity and image. Editors and publishers have a duty to get it right. It doesn't even put them in good light to publish poorly edited papers.