I have to get something straightned out.
The management will keep you as first officer to solve "this well known problem" ... or ... to avoid increasing the problem???
You have to raise your opinion to the management and show your FAA or JAA license and your logbook with your 12,000 hours in the right seat. (But try to explain it very carefull, because it is strange to have 12,000 flight hours and not being a Captain yet. I can imagine good reasons for that.)
After this you might get your upgrade on B777.
Marsalama, skilled and professional
First Officer Goatliner 