ALTDEV ALT OVERSHOT IN CLB. CLRNC INTERP DISPUTED.

Narrative

ATC CTLR ON FREQ 119.57 TOLD US TO 'TURN TO 320 DEGS AND CLB TO FL290.' PRIOR TO MGM CTLR'S DIRECTIVE; THE CTLR HAD A DISCUSSION WITH ANOTHER PLT CONCERNING THE COARSENESS OF The CTLR'S DEMEANOR ON THE RADIO. WE THEN CHKED IN TO ATC FREQ 132.97 AND TOLD THE CTLR WE WERE CLBING TO FL290. THE CTLR 'ROGERED' OUR CALL AND SAID HE WOULD HAVE A TURN ON COURSE SHORTLY. ABOUT A MIN LATER WE HAD A TA FOLLOWED BY AN RA BY TCASII. THE COPLT PICKED UP ACFT; AN MLG; IMMEDIATELY FOLLOWING TA. CAPT INITIATED AVOIDANCE PROCS UPON RA AND COPLT INFORMED ATC CTLR. CTR CTLR BEGAN TO CALL MULTIPLE ACFT TFC WHICH WAS VERIFIED BY TCASII. AFTER THE CAPT COMPLETED THE AVOIDANCE PROC WHEN CLR OF CONFLICT; COPLT INFORMED ATC CTLR THAT WE WERE 'RESUMING OUR CLB TO FL290.' THE CTLR THEN SAID WE WERE ONLY CLRED TO 'FL230.' SUPPLEMENTAL INFORMATION FROM ACN 251515: THE PROB HAPPENED BECAUSE BOTH CTLRS WERE BUSY AND A LOT OF THE COM BTWN PLTS AND CTLRS WAS GARBLED BECAUSE OF THE CONGESTION ON THE FREQS. PROB WAS RESOLVED BECAUSE OF TCASII. WITHOUT THE TCASII WARNING CONFLICT WOULD HAVE BEEN CLOSER. I ALSO THINK THE CTLR HAD OR WAS WORKING TOO MANY AIRPLANES.