I was offered and accepted an "upgrade promotion" at HKG check in (Central MTR Station) last night for LHR flight. Total was 2500HKD which at just over £200 seemed ok if a little expensive. At the gate I was given two vouchers - one for 1300HKD on official BA receipt labelled "upgrade promotion M to W class" and attached to that a 2nd invoice on plain paper for a "service fee" of 1200HKD. Question is - could I have negotiated a reduced fee and was this service fee a commission to the local agent? Anyone else experienced this?