So, I registered just for this thread. I unfortunately received one of the Spiritomb except that mine is level 50. I am more than willing to trade for a legitimate event Celebi if anyone is interested...
You should still have the Celebi as well. According to @FlareStarfire (on twitter), if you get both, you're forced to get the Spiritomb in order to pick up the Celebi. So you may still have the Celebi waiting to be picked up.