From what I remember, after a punishment there's a short time where you're locked out of honor.
Once that wears off, which it should have by now, you'll start accumulating honor again.
Once you're up to honor level 1, you'll start receiving key fragments again, albeit slower than at honor level 2.
Keep being honored, and avoid punishments and you'll soon* return to honor level 2 and above.
*I have no idea the time that soon means.
/edit
{quoted}
Generally the way it works is that getting a punishment from Instant Feedback will reduce your Honor level and "lock" it. A "locked" honor level means you will not receive Hextech chests or keyfrags. A chat restriction will reduce your account to level 1 (or to 0, if you're already level 1), whereas a ban will drop you to level 0 (dishonorable).