Of course they didn’t fire you. You didn’t just post criticism online, you mentioned a potentially unethical/abusive practice of not providing employees with decent lunch time frame, as well as making you guys work at your desks. Had they fired you, it would have potentially turned into a human rights lawsuit or something of that sort. Not to mention, it went viral and attracted public’s attention. No employer wants to be in the news for firing a young hard-working lady who expressed her voice against a possible violation.

I don’t condone emotional and impulsive decisions, but it sounds like you made the right choice for yourself. If you were unhappy, this was the perfect time to voice up your opinion and walk away.