I have a 2012 Ford Fiesta and on my way to Texas from Missouri it would not go into gears 1,3, and 5. It stopped as quickly as it started, but 5th gear would just rev the motor. There was no power to the wheels. Then there was the loudest grinding noise (sounded like rocks in the engine) in gears 1,2,3, neutral, and reverse. Fourth gear worked fine. When I returned home I was told the Synchronizer went out and caused the fluid to leak out and the gears were shot. I had the transmission replaced and before I put 50 miles on it the same exact thing happened. No 5th gear, sounds like rocks in the engine (even in neutral) and 4th gear works great. I was told I was sold a bad transmission and it needs to be replaced again. I could really use some advise!
It sounds like you had the transmission replaced with a used one. The one they took out was used also. So the transmission that is installed is only as good as the warranty that comes with it. If you have a warranty I would recommend taking it back.
I recommend Jasper Re-manufactured Transmissions if you have decided to go with replacing the transmission again. They have a great warranty that covers parts and labor. And they have warranty shops all over the US.