Didn't they decide to cancel the flight just a few days ago? I suspect that they simply haven't informed customer service on what to do yet and so customer service gives incorrect information.
Under EU rules, they have to rebook you in one way or another. However, since you aren't travelling until summer, they have got plenty of time to rebook you and so they may prefer to focus on rebooking passengers travelling earlier. I suggest that you wait and see. Don't try to cancel your ticket as you may lose your rights to rebook it free of charge.