By arena do you mean naughty mansion? Because if i remember correctly i don't think arena unlocks any new characters correct me if I'm wrong tho.
Also this time was the same as last time i got banned after one day after unlocking the character andriella and especially this time i tried not to speed run any content and only used gacha if the items were limited duration. Another thing to notice is i was still on version 1.2.134 when ver 1.2.135 was a day old i ignored the update because 1.2.134 worked fine and the app didn't prompt to update like it usually does.