1996 Saturn SL2 ignition cylinder lock

My problem started when my key would not turn the key lock cylinder, I could not turn it to the run position to be able to pull it out, I was advised by a guy at the parts store to drill it out, so that is what I did, in the process I went to far and drilled the stub that th key lock cylinder fits over. Any sugestions? Also what wuold the parf that I drilled into by mistake be called