This is a tough area of web marketing. Just a few well placed 'bad comments' on some major portals may outrank your website. If a bad review about you is the first thing people find when researching your company then your closing ratio is going to suffer.
So, no one can grantee that all the bad info can be whitewashed from the internet, there are a few good strategies. Here's what we recommend, and what we would do, if you hired us to fix things; (we are usually successful at some level)
I hired a roofer in Denver to replace a hail damaged roof on a rental house. They did a bad job and left a bunch of damage, including busting the garage door. I hired another company to fix up everything and paid them $1,600-. I then withheld that cost from the original company's bill. When they started to threaten me with a property lien I responded with multiple attacks online; everywhere from Google to Yelp reviews. Then I put up a 1 page blog, spent some time optimizing it, and it quickly outranked their company website. It was all true, with photos and descriptions. Here's their 'finished' trim work:
About a month later, the threat of a lien was replaced with a letter from their lawyer offering to fully discount my bill in return for removing all the negative comments. I agreed, they sent a 'new' invoice, and I removed most of the negative comments I had posted. Apparently, they lost a major commercial bid when the purchasing agent researched them online and found my review. So, this is just one example of how a reputation management issues can happen and then get resolved.
We always try to resolve the issue in exchange for removing all negative posts and comments. If we can't find an agreement there are other, more agressive approaches that we are not afraid to do.