Transmission/Valve Body replaced

I took my 97 Saturn to Earl's because of the automatic transmission not shifting into gear. I requested a used transmission put in. The first one they got from the junk yard was cracked and leaked fluid and had to be replaced. When I finally got it a week later, $1100 later, the car now doesn't shift into reverse easily so I took it back. Its under a 90 day warranty on parts only. They put in the valve from the cracked transmission and gave it back 3 days later saying it SEEMS better. After driving it for a day, it is still having reverse problems. Now they have to check with the junk yard to see if they can get another one and call back tomorrow. I feel I am getting the run around and they just don't want to fix it properly. If I wasn't already $1100 in the hole with them I would take it somewhere else.