Brackets to secure the screen to the bezel are broken

Yeah. You can glue them. One of the few times I would recommend super glue to be used in repairing a phone. It's easily available and should have a strong bond. You could also exchange your part, missing the brackets, but you may not want to wait for that, or if they're even willing to make an exchange

I'm not sure if this helps since I wasnt entirely sure what you went by bracket but i'm assuming the frame surrondung the glass/LCD assembly . I wouldnt really recommend do that as its much much better to just to return the damaged part. If this isnt ideal then yes you can replace that frame with heat and readhere it using my personal favorite. Serious Glue, as it works really really well on glass.