Cancellation refund promises, but no action

My wife and I booked air travel through Expedia from Boston to Madrid via Dublin on Aer Lingus. The airline canceled our outbound flight because of weather in Dublin. Neither Expedia nor Aer Lingus notified us of the cancellation (each claims this was the responsibility of the other party).

When we arrived at Logan Airport in Boston and learned that the flight was canceled, Aer Lingus put us on a direct flight from Boston to Madrid scheduled to depart the next day. However, the airline also canceled that flight.

We decided not to go on the trip because we could not get to Madrid in time for some important events. We asked Expedia for a refund. It has been nearly eight weeks since the original flight was due to depart. We have had 10 phone calls with Expedia and have spent more than 20 hours on the phone. Expedia representatives have told us multiple times that we would get a refund. Aer Lingus told us that it gave Expedia waiver codes for the refund the day of our flight, but every time we call Expedia, the company tells us it must call the airline, and then it tells us to wait seven business days.

Expedia has done nothing but repeatedly lie to us. Aer Lingus claims no responsibility whatsoever because we booked through a third party. It has become apparent that Expedia will ignore us until we give up. We will not give up. We also believe that if Aer Lingus or Expedia had notified us about the canceled outbound flight, we would have canceled our hotel reservations in time to avoid paying a penalty.