One morning a few years back we were over Bahrain and the controller was pretty busy with all the flights transiting his sector and sounded a bit stressed. Sounded as if he was from North America.
Another EK flight (whose radio voice sounded local) then came on freq to announce, "Bahrain, Emirati xxx at flight level 320". The Bahrain controller snapped back, "Emirati xxx.... I don't have an Emirati xxx on my strip. Go back to previously assigned frequency to straighten out your call sign"
haha, awesome!