Are you sure it's worth it? Unless the company ignores you and doesn't want to work something out with you, I don't think it's a wise idea to try to do a chargeback. If you do a chargeback, you are no longer the company's customer. That means, they can use whatever information they have against you (if they want to be nasty). I once bought something online and didn't recognize the name on the credit card statement. So I called my bank and told them I didn't authorize this charge. After filling out some papers, the bank credited my account.
A month later the company emailed me and wrote I was no longer their client and they forward the case to a collection agency. Then I realized I knew what I had purchased (but the website's name was different from the billing name; that's why I was confused). On the next day the agency called my employer and I had to explain myself. I resolved it in the end, but it gave me a lot of unnecessary stress. I don't know if it's totally legal to send a client to a collection agency, but it worked.