ALTDEV ALT OVERSHOT IN CLB.

Narrative

WE WERE CLRED TO; OR HAD BELIEVED WE HAD BEEN CLRED TO FL220 BY TYNDALL DEP CTL; A MIL FACILITY; AND EITHER BOTH MYSELF AND MY FO EITHER MISSED ONE OR MORE CALLS TO SWITCH AT ZTL OR WE HAD NEVER BEEN GIVEN A FREQ CHANGE. I HAD BEEN HAND-FLYING THE AIRPLANE UP TO CRUISE ALT WHEN THE TCASII SIGNALED A TA. THERE WAS ANOTHER ACFT AT FL210 AT OUR 2 O'CLOCK AND 7-8 MI. WE WERE AT THIS POINT CLBING THROUGH FL200 AND AT ABOUT FL204 I STOPPED THE CLB AND IMMEDIATELY ASKED TYNDALL ABOUT THE TFC. HE TOLD US THAT WE SHOULD BE TALKING TO CTR AND GAVE US THE FREQ. WE TOLD CTR WE WERE CLRED TO FL220 AND CTR IMMEDIATELY TOLD US WE WERE ONLY CLRED TO FL200. WE HAD BEEN AS HIGH AS FL204; POSSIBLY FL205. I INITIATED A DSCNT BACK TO FL200 AND WE WERE NEVER ASKED ABOUT NOR TOLD ABOUT OUR ALT DEV OR ANY TFC CONFLICT. AFTER I HAD TIME TO THINK ABOUT WHAT HAD HAPPENED AND WHY; I REALIZED THAT: 1) I SHOULD HAVE BEEN MORE AWARE OF OUR POS IN RELATION TO OUR POINT OF DEP. WE WERE 74 MI AWAY FROM PFN AND CLBING THROUGH THE FLT LEVELS. I SHOULD BE TALKING TO CTR! 2) OUR FILED ALT WAS FL200. WE GET ALTS DIFFERENT FROM WHAT WE FILE BUT NEVER WITHOUT AN EXPLANATION. EITHER WE HEARD WRONG; WERE GIVEN WRONG; AND READ BACK WRONG WITHOUT THE CTLR CATCHING THE MISTAKE; OR JUST PUT THE WRONG ALT IN THE SELECTOR AND FORGOT. 3) SHOULD HAVE GONE RIGHT BACK TO FL200 INSTEAD OF LEVELING OFF WHEN I SAW THE TFC ON THE TCASII AT FL210; I SHOULD HAVE FIGURED SOMEBODY WAS WRONG. AT LEAST I DIDN'T CONTINUE THE CLB. 4) WE (THE CREW) WERE ON THE LAST LEG OF A 4-DAY TRIP AND WERE TIRED; NOT SO THAT WE WERE NOT FIT TO FLY; BUT THE BORED; COMPLACENT TIRED THAT AIRLINE PLTS CAN GET WHEN THEY CAN'T WAIT TO GET HOME. I'M NOT SAYING THAT THIS IS EXCUSABLE BUT IT HAPPENS ALL THE TIME; AND NOT JUST TO MYSELF; BUT I MUST REALIZE AND IDENTIFY WHEN THIS HAPPENS AND BE EVEN MORE VIGILANT AND AWARE. I COULD HAVE PREVENTED THIS. THANK GOD FOR TCASII!