Jack, sorry you've been having problems updating firefox. Mozilla does not provide a phone number, and you should never have to pay with support. This website is the official support website for Firefox :)

Go ahead and try doing this: All of those Firefox downloads, delete them. You don't need them and they are old versions. It won't cause your computer to crash, so go ahead and delete them.

Then, open up Internet Explorer (make sure Firefox is closed for this part of the procedure). Go to www.getfirefox.com. click the big download now button. Then click the Run button. The new version of Firefox should download and install. Let me know if that works or not :)

As far as I know, Mozilla doesn't have any paid support service. There are lots of other companies that advertise paid support for desktop software including Firefox. Maybe you called one of those other providers??

Anyway, I suggest dragging all those exe files on your desktop to the recycle bin. They are all out of date.

Before upgrading, have you considered making a backup? Your bookmarks and other Firefox settings should be safe during an upgrade, but better safe than sorry. This article describes how you can back up: Backing up your information. For example, you can copy your entire Firefox profile folder somewhere outside of the Mozilla folder.

To get the latest Firefox, you can try either of these:

(1) Help > Check for Updates - this should work automatically

(2) Download the installer for Firefox 12 from http://www.mozilla.org/firefox (green button) to a convenient location, then double-click to launch it (Firefox needs to be closed)

After you see Firefox 12, the user interface will look different. For tips on how to restore features you miss from Firefox 3.6, you can ask questions here. For a little advance reading, check out this article: Make Firefox 4+ Look Like FF 3.6 | Computer Tech Tips.