Not a mind reader, just a waitress

I HATE IT when people won't tell you what they mean!
I work at U.P.D., University Pizza and Deli. and I love working there. I love the labor of working in a restaurant and I did love the people. Actually the thing is I still do, they're really an very interesting bunch of characters, no matter the current frustrations. Here is what has been happening, just the facts, so you can tell me what you think should be done in a situation like this
When I came back to school after break though I wasn't on the schedule. No problem, there was just a class and work hours conflict. I talked to my boss and manager about it and then rearranged my classes so I could work. I was promised a place on the schedule the next week, and got a few hours helping out at lunch time.
On the last shift I worked I had a spat with a coworker. She was new, and working the cash register while I served out the food. I noticed she was writing down a whole line of people's tickets before she would take the stack of them back to the kitchen for the two cooks to whip up all at once, and for me to dole out all at once. This also means that the person at the front of the line waits longer than the person at the back of the line. It was the first mistake I ever made on my first day and Akram had quickly got onto me about it. But Akram wasn't there and so I told her, but she began arguing with me. So I, taken aback, repeated the above logic a bit more concisely and then rushed to deliver the pizza that had just come out. When I came back though she was doing the same thing. I don't remember what I said first but she started to argue with me a little louder, though in the crowded restaurant no voice could dominate. I argued back. I was angry. I don't remember if I yelled or not but I'll admit it's possible. After work she asked me not to yell at her like that and I told her the truth. "I am sorry, I did not realize I was yelling."
Then I continued doing my job.
The very next week though I still wasn't on the schedule. Further more the restaurant has even hired a new waitress. At first I thought that because of this and the fact that Akram, my boss had just laid off a cook recently I thought I was next in line. But after a week passed with no explanation I went to my boss who told me again that he would talk to Kynsie my manager and get me on the schedule. He also made some remark about working as a team and not yelling but it was not specific enough for me to legitimately respond to it more than an "of course" I am not worried about Akram though, he is a good man and i know he gives everyone the benefit of the doubt.
Still I wondered about his words so I found my manager on facebook and sent her this message:
"

Hey,
Is something going on at work?
I've asked to be on the schedule and even switched around my classes so that I could be on the schedule and I'm not.
I just want to know whats going on. If you can't put me on the schedule that's fine I'd just like to know for sure so that I can find another job soon if I have to, and if I've done something wrong with work I really want to know so that I can make it better. I like this job and I'll do what it takes to get the work done I just need some clarity here, what is going on?"

This is her reply: "First of all, i DO NOT

appreciate being confronted about work stuff in my private life (here on face book for example). Secondly I'm just not sure why you have not caught on yet but whatever, I am not going to put you on the schedule. And i will not be responding to any work related messages you send me on face book."
"Sorry" I said, I just kept missing you at work."
So tomorrow I'm going to UPD to ask her, is this a temporary lay off? Can I feel free to find another job or I am I suddenly going to appear on the schedule one day with no notification like how I was suddenly dropped from it? Also, WHY am I not on the schedule. Just give me something! If I don't do my job right, tell me so I can do better. If my coworker has blown that little incident out of proportion let me defend myself or apologize again if need be, and if its simply just that they can't afford or have to many waitress, I still would like to know so I can stop wondering! I JUST WANT TO DO MY JOB! I have no other motives than that. I can't read minds and just want some answers!