Starting with a sigh.
I cannot imagine why you would purchase Belladonna/Atropa belladonna/Deadly Nightshade on purpose. That being said, many seed sellers confuse this plant with other similar-looking plants.
What you have might be Solanum nigrum aka Black Nightshade.
Or it could be Solanum americanum aka American nightshade; I know it as Hierba mora and grow it both for the local Latino community and for the Mockingbirds that love to eat the ripe black fruit. (I myself do not eat the leaves or the fruit.)
Whatever you do, please do not consume the foliage or fruit of any plant without obtaining a positive identification from a trusted local source.
