Ford Focus Electrical Glitch?

We took our 05 Ford Focus into the shop to get a leaky master clutch cylinder replaced and asked to have the slave cylinder replaced too. The mechanic turned out to be not the most stand-up guy. He gave us back the car after charging us more than the estimate without having fixed the slave cylinder. Furthermore, the check oil light is now staying on (even when the car is off) as is the door ajar light. The oil level looks fine and the doors are closed. What did this guy do to the car? Is there an easy way to fix it?

Also, it stops flickering when the car is on. It’s only flickering when the car is off.