Transmission problem in 2007 trailblazer

I don’t know where to start .. hopefully someone
can give me an idea of what’s wrong with it.


I have a 2007 Chevy trailblazer and in 10/2019 it
broke down transmission went out after constantly
taking back to my dealership because the fluid was
leaking . They took it to Chevrolet and I spoke with
someone there and they said the transmission was
leaking into the radiator or the raidiator was leaking
into the transmission I can’t remember but this was
after my dealership was supposed to fix the leak ..
my dealership told me the transmission went
because I was driving it in 4wd (which I wasn’t) so
another transmission was put in  got the car back
12/2019 fast forward a couple weeks I’m having
problems with the new transmission it’s
downshifting while on the highway I believe it was
3rd gear that kept going (not sure) so I again take it
back to the dealership and they have a solenoid or
something dealing with shifting put in I think it’s
working .. it’s NOT... so I continuously keep calling
to try to get it fixed and can’t get an appointment ..
well I believe drive and overdrive are gone... I can
still crank it up to move it if need be but can’t drive
it so I took it off the road early 2020 I was over it ..
it’s 2021 and I’m tired of looking at so I wanted to
possibly get it fixed ... so could it be something that
needs to be replaced in the transmission? Need to
get another used transmission? Rebuild the
transmission??   Please give me advice/opinions..