Never! The district managers have the worst management skills I have ever seen.
They have unrealistic goals for their empolyees. All they care about is selling phones. If you are doing a really good job but is not selling phones, you are going to get written up. If a store does not sell 30 contract phones the store is apparently doing a bad job.
Even if you work in a city where most people do not have good credit, the city I work in has a monopoly when it comes to phones, and it is a very small town and our store is not in a great location. Also, they came out with a list of people in our district they say are doing a bad job. More then half of the people in the district. More then half are going to get written up.
If they fire that many people, they are going to have so much fun paying for unemployment. And they really should not come out with a list.
If they have a problem, they need to talk to the employees in private.