Missing miles query

Hi all,
Noticed on my FC account that they had not credited my miles and tier points from my return trip from JFK. This is not unusual so I used the 'claim' button but got this message:
Now what is confusing me is that I got the miles and tier points for the outward journey which was a Z class, as was the return. The only difference I can think of is that the journey outwards I was ag, and the tier points I was given for that flight took me into au. Therefore I have a new Au membership number for the return. Could that be it?
Obviously I need to call the FC to discuss, but thought I'd float it on here first in case anyone has any experience of this?
Cheers
Noticed on my FC account that they had not credited my miles and tier points from my return trip from JFK. This is not unusual so I used the 'claim' button but got this message:
Unfortunately we are unable to process your request. Flying Club Miles and Tier points cannot be earned on this ticket type and therefore cannot be claimed retrospectively. Please refer to Flying Club Terms and Conditions.
Now what is confusing me is that I got the miles and tier points for the outward journey which was a Z class, as was the return. The only difference I can think of is that the journey outwards I was ag, and the tier points I was given for that flight took me into au. Therefore I have a new Au membership number for the return. Could that be it?
Obviously I need to call the FC to discuss, but thought I'd float it on here first in case anyone has any experience of this?
Cheers