Work refused my days off!!!

This is more so a rant than anything...

I requested the weekend of my baby shower off (THE BABY SHOWER HALL IS ALREADY RENTED) I have family coming from out of state and my best friend coming from across the country... and for some reason they refused me for the last weekend in July that has no events at my work that weekend.. it’s nothing significant. And my work REFUSED IT ! And I don’t understand it !

UPDATE: it’s a HUGE company, it’s Lowe’s, and I’m only a cashier. There are PLENTY of other cashiers and even the front end management don’t understand why I would be denied for it. I have to speak with the assistant store manager.