Things can go wrong. I am a person who believes in giving the benefit of the doubt, but sometimes things go wrong when you have an interaction with a company. Maybe you received a defective product, or maybe you just can't get the darn thing to work!
You can, of course, go to their web page and try going through their "Frequently-asked questions". I will do that. But only after Googling. If I want to say, upgrade to Quicktime Pro, I will Google "Upgrade to Quicktime Pro". In addition to getting information from the Quicktime page, I will get hits on comments people make on blogs, such as, "Quicktime has a problem upgrading the current version. Reinstall the old version to upgrade to Pro".
If this doesn't work, don't be tempted to pick up the phone. Companies just don't work that way anymore. If you're angry and frustrated, go hit a punching bag or something. If you want the problem resolved, do this:
Most web pages will have a contact page. No, not a telephone number, but a way that you can write to them and they will will email you back. I've done this many, many times. Companies want you to be happy with their products. They will write you back.
If you've been scammed, you are out of luck. You may want to post something on Twitter or YouTube but only if you're sure.
Give the benefit of the doubt.