Well AMP told me to talk to my bank. My bank had told me to talk to whoever owns the UK account where the funds were deposited (I think BMO). So I called BMO in the US, they told me they'd help but I have to go back to AMP (which I've done).
I seriously feel bad that it's taking so much effort to track this down and solve this problem. Anyway, I'll see what AMP come back with.