Drive belt replacement involves a package of parts that wear together;
Belt, Tensioner pulley, AND both idler pulleys (3 if you have dual alternators).
Did your Tech also swap those two $17 items at the same time?
Also, look at your pulley on your alternator.
Does it have a large nut visible in the center?
Or does it have a flat disc covering the front of it?
If it's a disk, that's a clutch pulley and they can fail and leave an annoying chirp like a belt does. The Alt will test fine, but a stethoscope will reveal the source if it is the pulley clutch. As well as if it's coming from the PS pump. AC off will rule out the compressor as a source.
2007 LBZ 3500 LT3 DRW Crew Cab, Sulastics, Putnam XDR 15K, B&W 30K-Turnover GN+Companion, Ride-Rite Air...EFI'd by Rob
2008 LMM 3500WT DRW Crew Cab, 8 'Flat/GN, Workforce Alum Toolbox, Ride-Rite Air Use-ta Haves 2006-6.0 3500 WT DRW ExCab Flatbed, 2005-LLY 3500 LS DRW Crew Cab, 2002-LB7 3500 LS DRW Crew Cab I Live my life in such a way that when my feet hit the floor in the morning...Satan shudders & says "Oh shit, he's awake!"