2012 Prius C won't start after replacing battery

My Prius C gave me the CHECK HYBRID SYSTEM STOP THE VEHICLE... message a while ago.
After I stopped it didn't start again I ended towing the car to the dealer. A few days later they called and tell me car is ready for pick up. They reset and erase message, car was running but they recommended to replace the hybrid battery for an exorbitant price. I was also told that I could reset that message with a regular scanner as far as the car was still running.
For a while every time the message showed up I would reset it and keep driving. I didn't even need to stop the car and I had my scanner connected all the time for a quick fix.
My daughter borrowed the car and even when she knew how to reset it drove it till battery drained.
So now I checked the Hybrid battery and all cells seem to be ok and around 8v.
Replaced 12v battery as the one I had was 5 years old so I thought it was not a bad idea to get another one.
When I try to start again it goes now to READY for a few seconds and then the CHECK HYBRID SYSTEM message shows again.
Any suggestions before I go back to the dealer to reset it? I know it will take days for them to see the car and minutes to reset it so I'm trying to do it myself and save time and money.

 

Checked both and they're in good shape.