Vehicle written off and repaired again.

Hello, I had an accident on the 31st of January, Upon feedback my car was declared a write off. I called again to enquire and they told me the same thing again that my vehicle is written off, Then suddenly my car was going to get repaired, I didn’t understand how a vehicle can go from write off to repair. Renew-it repairers called me today to let me know my vehicle is ready. I waited while they were doing finishing touches. The problem started when I had to receive the car. It did not start at all. Which implicates the damage on the vehicle was indeed a write off. I’m saddened by this because it means if I had to take the vehicle it’s going to start giving continuous problems. Since it didn’t pass mechanic.