A slight delay in getting your referee reports for that article? Try the following approach. First, accuse the editors with something like:
Such behavior is a violation of my scientific work as an author. It is most uncollegial and inexcusable.
Rant on for a while … and then close with:
If you do not wish or are unable to deal with this matter forthwith, I shall be forced to pursue legal procedures.
Such genteel behaviour will guarantee you favourable referee reports.