My understand is within D-45 days the seats will not automatically drop back in even if they were from the guaranteed seats. Aside from Wed 12th the flights don't look particularly busy so something may pop up, though getting return seats to match up may be tricky. I'd definitely push them via a complaint, either they can appeal to rev man to open the seats up (no loss to them, you're taking the two seats you had anyway) or there is a budget in the call centre to fix mistakes I believe.

Send the complaint in via the CEO for best chance of getting it in front of someone ASAP