Originally Posted by
SFO777
It's not at all clear that they were two separate PNRs. Indeed, OP stated "AA made no effort to get me rebooked on NZ" which to me suggests a single PNR, which is why I suggested the CC dispute route.
Had they been on the same PNR, Air NZ would not have charged him.
I am going to assume they were not.
That is the problem with 2 different tickets on 2 different carriers.
(additionally AA does assist when the other carrier is OneWorld )