I will sit with my 14-day ban for 1 game when I didn't say any racial slur and just called him out for inting.
Punishments run on a ladder.
http://tkwa.re/leaguereporttiers
For you to have gotten a 14 day ban, you either had just finished serving a 25 game chat restriction, or you used hate speech. It's about consistency - if you're consistently toxic, the punishments get more and more harsh. Your next step FOR ANY OFFENSE, no matter how small, is a permaban. Please take the warning seriously.
If you posted the chatlog (it should be on the screen when you first log in), we could tell you exactly what's wrong.
All that said, keep in mind that placements are going to put you in games somewhere between bronze and silver. This was your very first placement match. You have nine more to go, so relax a bit. You have no right to flame someone to the degree you did to get restricted just because they're bad.
You are not a challenger smurf. Know your place and drop the entitlement.
That said, the Nasus you were playing with is a level 30, unranked, on his very first placement match also. If he keeps playing like that, he's gonna wind up in low bronze. Both of you have no history in previous seasons, so you're both complete wildcards to the matchmaker, there's nothing Riot could have done differently here.
At your MMR, you're going to have a lot of questionable teams. Part of the ranked climb is controlling your tilt and dealing with bad players, because this is hardly the first or only one you're gonna have. If you can't deal with that, League is not the game for you.
