I bought diamonds to buy the genetic test kit, but got the genetic scanner instead... Is there anyway to reverse this? Or flat out trade the scanner for the kit? What are my options?

As far as I know, the only thing you can do is contact Krinadon by PM and ask him nicely if he might either switch your purchase, or take away the scanner and refund your diamonds so you can buy the right thing. The exceptionals are untradeable, so no one but Krin can really do anything to help.