I'd suggest logging a call very quickly - not something that can be fixed via the forum.
You could try ...
bpexpdate -extend_expired -backupid <backupid> -d <date in future to extend to>
I always forget about the extend_expired option. I think this came in at 7.7.2 via an EEB, but is there by default on 7.7.3.
What is the case number