The issue here is that the OP was given incorrect information on the phone (and I have no reason to think that he is making it up). This is unacceptable no matter how much or how little one pays for one's ticket.

Do Ryanair record telephone calls?

And I don't understand why the agent would have misinformed him. Was she a new employee who previously worked for another airline and got confused between her old job and her new one? Or was it an outright revenue-generating lie?