You're right I was/am upset the rep rendered my phone useless. I get what you say about the sim card tray too. But at no point would I expect a S8, and ascribing that motive to me is unfair.

I need to emphasize that I didn't go into the store trying to get one over on T-Mobile. I was there because I bought a $280 phone for my daughter and while that was happening I asked them to look at my phone which at that point was fully functional (for me anyway, I understand your point about the tray). The rep put me in a bad spot by ripping my sim card tray.

As far as my expectations, I never asked for an S8 or anything like it. I either wanted my phone to work again, or replace it with a new one of the same model. Or if they only have S7 flat left in stock then I wanted a credit to account for the difference. Maybe that's unreasonable on my part and from the replies here it would seem so. But I still think it's shitty customer service considering I had just spent $300 in the store and I left with my phone being fully broken.