HELP! Prius Gen 3 Brake Booster Bump Problem

I experienced a brake booster problem where my hazard warning lights came without the car being in use. I discovered it was a brake booster pump problem so I got it replaced.The garage who replaced the booster pump got everything back working except the following. When they got it working the hazard warning lights came on, but they couldn't get the turn signal indicators to work. They searched for a solution and had to cut a wire to the hazard warning lights to get the turn signal indicators to work. The situation now is the hazard warning lights don't work. The garage told me it's an inbuilt factory fault. Has anyone experienced this phenomenon and if so how did you resolve it and get the warning lights and the turn signal indicators working as normal. Sincere thanks for any solutions.