Hi bud. Sorry about your experience. There is a blend of things going on here, like you said, that implicate both parties.
People all over the world are being trained by corporate managers to use "open body language," "top-down selling" and "add a little personality" to this here script. The biggest challenge, and what is slightly anti-intuitive, is that when you are doing it self-consciously it is difficult to be genuine. For some of us, it feels like we are manipulating people and this can result in feeling downright sick sometimes. Unfortunately, in the society we have built, this kind of manipulation is great for selling. Selling is great for the economy and prosperity of the institution and your own pay. It's weird, but it's the case. Likely, you were a little too easy to concede to a customer's objections (they hate that) or, you spent more time selling teas that YOU like -- which should make them happy, but it won't if those teas don't have high margins.
Now I may have misunderstood, but I believe you mentioned that you missed a couple shifts. Am I right about that? If that is the case, they have a very good point. Though I don't work in retail anymore, I did for 5 years. Any place I ever worked a "no call, no show" was grounds for immediate dismissal. Only once. If this did happen to you, my best advice is to acknowledge to yourself that you made a mistake, internalize the lesson and move on. Growing is painful, especially when we don't like the source of the lesson -- in this case, Teavana.
I definitely sympathize with your disdain for the managers. I hate that silly "high-five" BS that demands your enthusiasm. Make me puke. Likely, she learned that at some managers team-building thing.
Regarding your check, just walk straight back in there, don't be rude or hurt, and ask for it.