Transmission problem or not

I have a 2008 Prius with 135000 miles. A month ago the dash lit up like a Christmas tree so I called Toyota and they said to get it checked right away. It was after hours so Pep Boys looked at it and said they thought it was the tranny (or whatever it is called in the Prius) but they couldn't work on it and I needed to take it to a dealer. Picked it up the next morning and lights were all off so thought, make a go for it home 3 hours away. Got an hour out of town and lights came on and car slowly bogged down on the highway but I was able to limp to an exit and get off. Tow truck towed to nearest dealer. They said codes said it needed a transmission. They wanted about $5000 for a new Toyota tranny so opted for a used - 80,000 one for $2000. So things were going good for a month and then again, lights all came on and it bogged down. Had it towed to nearest dealer. They said codes said it needed a new tranny. Called dealer that put in tranny (which was an hour away) because it has a one year warranty. They said they would work it out with the other dealership. Called them back and they said they had talked to the place where the used transmission was purchased and apparently they told them to check something else and they then came up with no it wasn't the tranny but a different code came up and it was going to be another $2000! Called original dealer back and they said they would tow it to their dealership and check it out. They do a diagnostic on it and there are no codes - they can't find anything wrong. They said all codes were wiped clean when they installed the tranny previously and that there is no indication of any other codes since they replaced the tranny. That seems weird because all the warning lights came on when it broke down. And wouldn't the codes the other dealer saw be seen? Wouldn't the codes show up? They have had it for 4 days and still can't find anything wrong.
1. I'm feeling like it was originally misdiagnosed and I paid for a tranny I didn't need.
2. Why would the other dealer get two different codes?
3. Why would the codes be cleared?
4. What's wrong with my car? It's driving me nuts, not to mention the fact it keeps breaking down 3 hours away from home! Anybody with any ideas out there? HELP!

 

But the dealer that installed the new tranny has had the car for 4 days and no codes are showing up. It took a month for it to act up again. I'll probably end up picking it up because they can't find any codes, get half way home and break down again. That's my dilemma....

 

They tell me they have been driving it as their courtesy car and the service manager is going to drive it 40 miles home tonight. Hopefullly something will kick in.

Also, I did call the other dealer that got the codes but had to leave a message yesterday. He hasn't gotten back to me so I'll call again tomorrow. Good idea. I don't know why the dealers don't talk to one another..

 

That would make sense. I would think their techs could figure that out but I'm assuming the technology on these cars is such that no one has a handle on them yet. I suggested they call their Toyota Tech hot line. They did and the response was, they need a code!

 

Yes, that's my understanding of what they are doing. They are trying to duplicate the problem by putting miles on the car. And yes, they told me that after the fact. I'm quickly loosing faith in Toyota.

 

Another day and still no answers. They want to hold on to my car and keep driving it until the problem materializes again. It took it a month and several hundred miles the last time. Surely they can go beyond their computer and figure this out.