We don't give up rights by applying for or holding an FAC. We are paying for a service, the Police would do well to remember that. That said, i wouldn't write a letter of complaint but rather a letter querying why the process has taken so long - simply because it is more likely to acheive a result.
When I had my FEO round he said many FEO offices were under resourced as the process is not glamourous, it is not measured for perfomance and never attracts any media interest. So, some county's are short handed and others are not.
Finally, join the basc and make use of their advisory servic