You are entitled to payment for the article that she accepted, and I hope you receive it.
While I can understand the client's displeasure about the keyword phrase not being repeated as she instructed (yes, "what is capital gains" is an awkward phrase. but that's par for the course with some
SEO articles), her response was entirely unprofessional and harsh. She said "by Monday morning"--11 AM her time is still Monday morning. It sounds like the article could have been corrected without much difficulty, if she hadn't flown off the handle with her "you're off the team!" outburst.
Move on...and good luck!