Male Betta and Fruit Tetra. Can you help?

if you don't want me to tell you to do the right thing and add a divider or separate the fish into different tanks, you probably don't want me to tell you to return a fish. you probably also don't want to hear that fruit tetras are injected with dye. they are black skirt tetras that are bred to be clear so they can be dyed. black skirt tetras are known to fin nip, especially when not kept with at least 4 other fish of their kind. sorry you didn't do your research.