Originally Posted by
GregMM
You're welcome to try, but according to the Terms and Conditions at the time of purchase, it does mean you're not entitled:
Economy Plus purchases are automatically refunded after scheduled departure in the event of flight cancellation, change to a different flight or when travel is not completed in Economy Plus seating. In all other cases Economy Plus purchases are nonrefundable.
It's just worded that way to keep it simple. As the agent told me on the phone in no uncertain terms, if you buy an E+ seat at one price then are moved to a cheaper/less desirable E+ against your will due to, for example, an equipment change, you are most definitely entitled to a refund of the difference in price.
In fact because the pricing is dynamic, they may refund your entire E+ purchase price. But again, only if it happens against your will.