Sounds like OP was able to get them to waive the demand to pay the fee but I'm surprised he had to complain at all. Even if the full flight with the FI segment is not on a single itinerary, the change was created by AS. I always thought it was the policy that if they change your flight which results in a delayed arrival time, you could either get a full refund or a "free" change to an earlier flight - even if you don't have status.