did your link start with web.roblox instead of www.roblox? if so then that's probably why you got inexplicably banned, web.roblox is for users who are under 13.
if it didn't start with web.roblox then i dunno why you got banned either.
oh my god it did, i was signed in to an alt account att which had an unset birthday on it, and sent the link to my main. why the hell wouldn't they make it clearer
