["I have done my grocery yesterday. I didn't pay for a chocolate bar. I feel bad about it.", 'Man, that sucks. Are you going to go back and return it or did you eat it already?', "I didn't eat yet but I can't return it."]
I say in that case don't worry about it. Mistakes happen.
I have done my grocery yesterday. I didn't pay for a chocolate bar. I feel bad about it.