But if you have an indefinite ban, you are not allowed to appeal for a year. In other words, IF you are banned improperly, but indefinitely, there is no way back for at least a year.
News to me. If you are banned by CSN, you should be able to (and, as far as I know, can) appeal immediately to ArbCom. They may not accept the case if they feel there is nothing worth discussing, but I know of no rule which prevents you filing a case (of course, you're blocked, so you'll have to file it by emailing an arbiter).