Bans are not made immediately. Cases are reviewed by moderators, and when a ban is in place, it means the case was very bad. Whatever you had done that earned you a permanent ban must have been very serious enough for the moderators to permanently ban you.
Here are the things that can earn a warning to a temporary ban, permanent ban if the case becomes more and more severe:
Trolling, Flaming, Spamming.
Here are the things that can earn you an immediate permanent ban without a warning to come in place.:
Exploiting Site Glitches for Personal Gain
Source: The Rules & Guidelines of Gaiaonline
The Black & White Offenses. These offenses may either come with a warning, or an immediate permanent ban once caught.
Sexual/Graphic Material: Depending on the content of it, you may either get yourself a warning for posting it, or you may even receive a permanent ban.
Being Underage: This is the only permanent ban that can be reversed. As stated here in the PSA: Topics you should avoid making jokes about on Gaia in the Chatterbox, if you have openly admitted, or even joking about being underage, can earn you an immediate ban without warning, because Gaiaonline is bound by the COPPA laws. You can file a ticket via the Help center through "Contact Us", you'll need to provide proof that you are over the age of 12 and under to redeem your account back.
However, Ban cases can only be reviewed in one year only. If it's been more than one year, Gaiaonline may or may not look at your ban case. But if you can provide solid proof that what you did was not bad, then you can redeem your account back.
Hope u don't mind me save-ing what u sed.