Clutch or Transmission toast?

So I'm getting ready to buy a truck from the boss that i drove for a couple years
and wondering if the clutch that was installed a year and a half ago was a bad
one or if something up with the transmission it self.

Here's the story they installed a clutch in the truck a year and a half ago and right
from day one i said its not right, because you put your foot on the clutch all the way
to the clutch brake and the trans would stop and allow you to put the truck in gear
like it should. As along as your foot was still on the clutch brake you could freely
move the stick to any gear. Now when you lifted off the clutch brake say an inch so
the the clutch is still engaged and trans will spin a bit locking the truck in gear and
having to force it out or step on the clutch brake again. If you have the truck in neutral
and step on the clutch brake and let out a bit and move the gearshift enough to rub the
gears you feel it spinning slowly and by the time you let out the clutch 3/4 of the way
the trans is spinning as fast as it was before you stopped it with the clutch brake. Its
the same when you coming to a stop at a set of lights. I'll come to a complete stop
in 4th with foot on the a clutch and want to go to first to start off, and the trans has
locked it self in gear has to be forced out, use the clutch brake to stop and then put
it in first gear.

So I told the dealer about the issue for months and it was adjusted at least 10+ times
and they kept saying everything was in spec and its supposed to do that which i know
is BS so I just gave up, cause our maintenance guy wont fix what the shop says isn't
broken. Its manageable just irritating.

So now that I'm buying the truck and can make my own decisions on repairs and use the
shops that i want. I'm relooking at this problem and was hoping you guys could point me
in the right direction as to whats going on oh I don't know if it matters its a 13sp 1850tq
trans.