Like the message says, you are probably banned for spamming or plagiarizing other people's posts. Those kind of bans are usually permanent.
What you can do is send an appeal to the email address that is displayed at the top of the forum after you login in. But pay attention that it's the correct email address. The thing you posted in your OP is not correct!

You may appeal your ban also by creating a thread in Meta from an alt account (in this case it's your Stefanie302 account) and explain why you believe that the forum admins made a mistake and how you have contributed positively to the forum. If you don't have a history of positive contributions, it's going to be hard to get your account back.

What you are not allowed to do is use that account to make other posts outside of your ban appeal thread. And you have already done that. Go and delete the post you make in the altcoin section otherwise this account of yours will also get banned because of ban evading. When one of your accounts is banned, you can only appeal and request for the ban to be lifted, but you can't participate in other discussions like nothing happened.