Your problem is bad build quality, not the spoke count. You need to either find a shop with a more skillful wheel builder or learn the skills yourself. Jobst Brandt's _The Bicycle Wheel_ is good.

The issue here is that spokes fail due to fatigue, with the number of cycles they survive (about 750 per mile) dependent on average stress and the magnitude of the variation (a heavier person causes more variation).

Wheels which have not been stress relieved have parts of the elbows which were never taken past their elastic limit and therefore have high average stress. After enough cycles all those spokes (especially on the rear drive side) will fail about the same time.

Wheels with insufficient tension (especially in the rear non-drive side) can have the spokes going slack and bending with the high stress from bending creating premature failures. The low tension also allows nipples to rotate and loosen which exacerbates the problem and means the wheels don't stay true.

Your machine built wheels failed because they weren't stress relieved and had some spokes at low tension . They would have survived if some one fixed that before you rode the bike. Other machine built wheels are likely to have similar problems.

The fix is to replace all of the spokes on the side(s) which have been breaking (they all have the same number of fatigue cycles and about the same residual stress so the rest should be failing in short order) with DT or Wheelsmith 14/15 gauge double butted with brass nipples. Set drive side tension to an appropriate level like 110kgf. Tighten the non-drive side enough to center the wheel. Stress relieve. Correct any minor problems. Assuming you correctly compensated for spoke windup the wheel will stay true until you put a bend in it. The spokes will last pretty much indefinitely, through many rims (even if crashed).