So I go to Starbucks and i order and venti strawberry refresher and a bacon sandwich and the total was 9.40$ so i paid with a 20 dollar bill. Keep in mind I only had a 20 dollar bill in my wallet. So she gives me .60$ back and i told her that i gave a 20 dollar bill. She called one of the other employees up to her station after i said that(which seemed really suspicious) but she kept saying i gave her a 10 dollar bill, And i knew for a FACT i gave her a 20. I wanted to be polite so i left but i should have gotten my change back.