Report it to Doc John if they are in this site!!! He doesnt tolerate that kind of fraud/abuse and neither should you!!
Hopefully you can print the poem you wrote showing the date being earlier than that scum bag's.
Take back your intellectual property and dont just lie down and try to be "understanding". Someone stole from you, then turned around and took your credit. You are seriously worried about hurting their feelings??? C'mon REALLY! Do the right thing which is stand up for whats yours. That person needs to be held accountable and you arent doing them any favor in the long run by letting them get away with this type of disgraceful behavior.
It's outrageous.
Dont be a victim.