Etihad denying compensation
A few weeks back, our stopover to Islamabad was cancelled on our return flight which delayed the trip 1d inbound and 2d outbound. Upon finding this out we submitted a request for compensation to Etihad for the changes as we read we were eligible. After a week or two, Etihad sent an email asking for us to confirm their flight changes- we initially didn't respond but felt like we had to upon them sending a followup email. My sister, whom had also booked with Etihad and had her flights reschedules, also submitted a complaint, and later called them asking for an update on it, upon which they told her not to accept the changes as it would make her complaint null and void.
I was wondering if this is valid? It doesn't seem right that accepting the flight would cancel out any compensation as the changes have still been made.