Button down Sweater Vest

Idk if you can tell in the pics but this sweater is a rich bright and vibrant shade of purple. It is so beautiful but as you can see in the last pic it doesn't fit me :( I can't button all the buttons. This vest is meant to be form fitting and kinda long. Not heavy at all could wear all summer. This vest is in like new, excellent condition. I've never worn it. But is for a small and will not fit medium.