There is a Business Campaign/promotional fare available from HKG and apparently this is what OP has purchased:
...
Fare class: I1PFHK52
Changes:
BEFORE DEPARTURE
CHANGES NOT PERMITTED
AFTER DEPARTURE
CHANGES PERMITTED.
NOTE -
CHARGE HKD 2000 FOR REISSUE/REVALIDATION
CANCELLATIONS
TICKET IS NON-REFUNDABLE.
...
A bit unusual but intelligible since the price is fairly good ex HKG in J.