1991 LeBaron steering play-gets worse over time

Hello:

About three months ago I had the steering rack, lower control arm, and
control arm bushings replaced on my 1991 LeBaron. Total out the door
with alignment was $724.

When I got the car back, it seemed to pull to the left. I took the car
back, they realigned, and when I got it back, it pulled to the right.
Oh well, I thought, I'll live with it until the next tire rotation.

Over time, I have had some steering play start to creep into the mix.
At first it was oh so slight, but now at Interstate speeds you have to
work the wheel to keep it in a straight line. I drove about 45 miles
on the Interstate the other night, and it wore my arms out!

I have read about steering racks being loose at the mount bushing, so
I put the car up on ramps and looked. Seems like the rack is tight in
it's mount.

My wife took the car to the grocery tonight, and now refuses to drive
it.

I am taking the car back to the shop on Friday; any suggestions on
what it could be? Is it possible that the rebuilt steering rack is the
culprit (If it is, I hope they warranty the rack).

Thanks for any advice, Bill