Engine does not start & P3000&C1259 on

Hello guys
I'm writting, all the way over the ocean from europe. Here, the ideea to rebuild a HV battery (traction) is not possible. I work at a Toyota dealer and recently bought a Prius I, the vehicle was fine until one of my mechanics left it inside the workshop in N for 5 days. After that the gas engine does not start at all, and only P3000 & C1259 appears on my techstrem dignosis tool. I belive that one or more cells are damaged. I read how to rebuild it, but i would like to know if somone here confrunted the same problem like I and may be, has another ideea how to start the car. The SOC is between 30 and 50%, and lowest block has 8 V and the highest has 11 V. Thank you!!!