This sounds like a Competitive Leaver Season Ban and not a full account suspension or ban. If that is the case you are banned only from Competitive Play. This occurs due to leaving too many games from Competitive Play (this includes all disconnections and crashes). Competitive Season Bans cannot be appealed and getting a Competitive Season Ban results in the loss of all end-of-season rewards including Bonus Competitive Points. Getting a season ban puts you one step closer to a Competitive PERMANENT ban (3 season bans triggers this).
Unfortunately all disconnections and game crashes counts as leaving the match and will be penalized appropriately. The game server has no way to discern a legitimate disconnection or game crash from one that is forcefully caused by a dishonest player to bypass leaver penalties. You can learn about this policy here:
Remember if you see the message, “Lost Connection to the Server” in the title screen or the message “Failed to Connect to Server” in red text in the text chat box, this means there is something that disrupted your connection to the game server and not a problem with the game server itself. There can be a variety of reasons this happens including those that don’t disconnect your computer from the Internet. There is great troubleshooting to start with that can most likely resolve most issues and I encourage you to check them out here:
As always if nothing in that guide works, please start a new topic in the technical support forum saying you completed these steps and additional advice can be provided.
I believe this user is not dealing with an account action, just a competitive ban. Its okay for them to ask for help (though we can’t do much about it). Arguing or presenting misinformation of account actions is against the forum code-of-conduct. Technically an account action is suppose to block that specific account from posting on the forums anyways (though many often still post through an alternate account).