Only success I've had when a charge-back was not an option was a shotgun approach.
depends on company but try and see if you can get your hands on an email directory. And hammer *all* the emails daily with resolution requests
Your details are thin so just going on assumptions. If they seem to have no plans to help you, than you need to be a big pain. Add a link at bottom of each email from ripoff report, resellerratings.com and a few other sites if you can [You need to file the posts naturally].
Companies don't really care about the reports in many cases, but it shows them you are stubborn and don't have plans to lay down. Depending on the type of business there may be some kind of consumer advocate site you can lodge a complaint. Again, companies don't really care, but if they think you are going to blast the internet with bad PR it can help a lot
The bigger the company, the more departments it will have. And the more email addresses. Some time on Google can turn up various email address sometimes.
It can be frustrating and time consuming but with enough effort they usually cave in at some point if it makes you go away.
Luck | 
