Cessna 400
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 50; Flight Crew Total 14000; Flight Crew Type 50
ATC Issue All Types; Conflict NMAC
Flight Crew Requested ATC Assistance / Clarification
Airspace Structure; Human Factors; Procedure
I was on an IFR clearance at 9;000 MSL direct to RMG VOR. We were in the vicinity of 12J (Brewton; AL) when I received a TA alerting traffic 400 feet below me and approximately 1 mile to my 3 o'clock.  I queried ATC about the traffic; but Controller did not respond.  Instead; ATC responded to an aircraft on another frequency.  I tried one more time with no response. The aircraft climbed to 200 feet below me and arrested his climb.  As I was about to disengage the autopilot; I saw him pass beneath us at my 10 o'clock position.  Up until that point; I never saw him visually as we were in a low wing aircraft.  He was in a left turn and appeared to be level or in a descent.  After reporting the near miss to the Controller; the response was; 'Roger.'  We were never given a traffic alert by ATC. The aircraft was a red and white single engine turbo-prop; tandem military trainer.  There was an active MOA (PNS North) that began 1;000 above us (10;000 ft) and extended to FL180.
Columbia 400 pilot reports an NMAC at 8;000 feet with a military trainer near Brewton; Alabama.  ATC did not report the traffic; but TAS provided a warning.