I guess you are here because your Pinterest Account was Suspended... I know how that feels! Yes, even I have been suspended from Pinterest - but got account back following below steps.
This is especially important now (FEB 2020 onwards) after Pinterest changed how they view content and do not like you to curate content too much.
How to Get Banned by Pinterest
Let's look at why you were banned by Pinterest. There are few reasons why they kick you in the jail.
If you are uploading content that Pinterest views as spam - there are few categories they do not like. This also include spammy looking pins - I dont think I need to give you an example as if you are part of group boards, you must have seen these pins - yep the cartoony looking ones telling us what we do wrong or how to fix something with awful text overlays.
You post a pin with misleading link to it. This can happen when someone steals your pin and adds their own link to it. So nothing to do with you really. I am mentioning this because you should periodically check your pins with reverse image search to ensure nobody is stealing your best content.
Repinning too much
Now that Pinterest views content differently, curating lot of old content does no favors to you. If you have 30 repins on daily schedule and repinning your own account too many times in short period of time - you will be flagged.
Commenting, liking and following too much
If you comment / like too many pins or follow too many accounts too quickly, Pinterest assumes it is a bot at work, not human. If you ad an link to a comment, you'll be kicked out before you know it.
Messaging too many people
If you apply to group board you might be sending many message to other users. This is ok just don't add your website link (or any link) to the message.
Anyways group boards are bit of a past now so this should be not an issue going forward.
If you are genuine content creator on Pinterest, this is more likely why you where banned. I was banned because of a bug in the system.
Read Community Guidelines for further information.
How to get Suspended Pinterest Account Back
Step 1 Right after you get suspended and if you believe it not called for (aka you are not a spammer), go to your email and find an email about suspension.
You'll find a link on the email to appeal your suspension. I was suspended by accident (a bug) and clicking that link got me out of the Pinterest jail.
Step 2 Wait.
It might feel like forever but you just need to wait for them to process your appeal. It normally takes just 1-2 days. If your first appeal did not work, you can appeal once more.
Step 3 Contact Pinterest via their Help Centre page and look for account suspension.
You can lay out your case and get account suspension reconsidered. First be apologetic and friendly - your message will be read by support staff and they can either help you or not...
And explain what you where doing on Pinterest at the time of suspension and why it was uncalled for.
Step 4 Check your email every 10 minutes waiting for your judgement.
Step 5 Get Email with Title "We reactivated your account" and do a happy dance.
Step 6 If you did not get above email, appeal again. Especially if you got a canned message from Pinterest with no name at the bottom of the message.