Yikes, I forgot about installing the SSD in an OptiBay. I think you should return it if this is how you've installed the SSD. I can easily imagine the SSD bumping against the insides of the MBP. And the tape just makes everything tacky.
But if you put the SSD in the normal drive spot and your mechanical drive (if you're using one) in the OptiBay, everything would fit nice and tight and your Mac can hibernate with the SSD. Then, it's less necessary to go through an exchange.
Still, I think you should return. You should get what you paid for, and the plastic bracket does have a functional purpose.