At the time of the install we thought all was okay. John was friendly and I thought he sounded like he knew what he was doing. The job was completed in good time. Over the years, the fireplace was used maybe 10 times. We kept noticing smoke filtering in the house. The last time we tried it 2 years ago we had the fire going for a while for a family gathering but finally had to put the fire out due to smoke. That was the last time we used it. Not having any money to get it looked at, we put off getting it fixed or cleaned.
We finally got around to calling in some chimney sweep companies to see what they could do. We got the same response from 5 different companies. The liner is too small for the fireplace. It is 8 inch round and it should be at least 10 inches square for the size fireplace we have. Even worse than that, the liner was installed in two sections. The two sections were not properly clamped together so they have separated. The fireplace is considered unsafe and they warn that it should not be used. So what to do. I called Classic Chimney Sweeps. The first time I called, a gentleman answered and I told him my dilemma. I told him the contract we had from 2008 has a lifetime warranty on the liner and besides being the wrong size, it was broken. He said John was in the field and would call back the next day. That was more than 2 weeks ago. Since then, no one is answering the phone, and the messages I left are getting no response. We sent a registered letter to the company address (actually a house address) to try to get a response from the company. An authorized person was not able to accept the letter and the post office left a notice for them to go pick the letter up at the post office. So far, a week has gone by and no one from the company will pick it up. 
Meanwhile we've had a mason out to give us an estimate on fixing the mess. He said there was an additional couple issues. The liner was essentially cemented in (I don't know the name of the material used but it sounds like it is commonly used by some installers) so would be harder to remove. Initially we were told the chimney may have to be totally torn down - even inside the house - in order to remove the liner. Fortunately the mason said the chimney was short enough so he could get the liner out with some device. He also noticed the area at the bottom of the liner was not properly mortared and the liner didn't come down far enough so smoke would filter through those bricks. His estimate to fix all the problems and make the chimney usable again is 4 times what we initially paid Classic Chimney Sweeps.
So lessons learned. Do not use a chimney sweep company unless you know they are certified by the Chimney Sweep Institute of America. And most importantly, DO NOT use this company without having a second party who is properly certified inspect the work done before you pay Classic Chimney Sweeps anything.
(I have pictures of the problems, but don't know how to attach them.)