Welcome to FlyerTalk.

First, the agent you spoke with gave you incorrect information. Unfortunately, this is not terribly uncommon - the agent essentially blew you off with made up crap instead of looking up the rules available on every reservations agent's computer. (You'll often see "HUCA" used here - hang up, call again - because of this problem.)

If you call again, ask about your PNR (six letter trip identifier) and the Y1ERTJ fare class. (It's a form of full Y, not discounted economy like M, V, O, Q etc.) And keep your ticket number(s) written down as well - begin with "001" - in case of issues, once they're issued as an e-ticket.

Second, it appears your ticket is changeable without fees (but has some stipulated limitations to those changes) and is refundable in case of cancelation.