Would you tell me if there is any difference in meaning between the present simple and the future simple in the context below?
If you don't pay up, I file a lawsuit.
If you don't pay up, I will file a lawsuit.
I hear both the present simple and future simple sentence in this type sentences very often. And to me, a non native speaker, both sentences mean the same. But, my gut feeling tells me there might me a difference in meaning.
I've refered to grammar books for an answer but couldn't find it for this specific context.