Family Dollar review: Store closing early

On June 3 at 9:49 pm I went your store on sterlington rd to pick up a few items thinking I had 10 minutes when I get to the store the cashier said the store was closed I then replied its still 10 minutes to closing and he said the store closed. This isn't the first this has happened but the first time I'm reporting it, the hours on the door States 8am to 10 pm, why are they not staying open until closing time