The newer versions likely have not been released for your particular phone model. It's the same thing with new phones; my Desire is still on 2.1 while Nexus One and several other phones have 2.2.
The problem is that both my Desire and your Behold II have a custom-made user interface made by Samsung in your case. This makes the updating process more difficult, as Samsung has to make sure the new version of Android works with their custom interface.
A lot of phones that are older than a year stop receiving updates. What you can do is root the phone and flash a different ROM on there with the updated operating system, but without the Samsung-made interface (you would get the standard Android interface instead). Whether there are ROMs available for your particular model or not, you're better off asking someone else. I'm not a rooter and I won't be until my warranty's run out and I feel like messing around with the firmware.