Fantana said that Zari is "dating kids she went to high school with".
Zari is 42 and her husband, Shakib Lutaaya, is 10 years her junior.
During Season Two of 'Young, Famous and African', Fantana, who was being cast for the first time, initiated romance with Zari's baby daddy Diamond Platnumz.
This brought tension between the two and it has escalated to social media.
In episode nine of the Netflix-produced reality television series, Fantana asks Zari to confirm if she is a cougar.
Zari calls her “a young slut.”
Fantana refers to herself as "a young, rich bitch."
Zari reminds Fantana that she is a billionaire.
Fantana tells Zari that she shares two kids with Diamond Platnumz but she couldn't keep him.
During the same episode, Khanyi Mbayi organises a meetup in which is invites Zari, Fantana and Platnumz.
It gets too heated up and Fantana says she would rather die than apologise to Zari.
On Saturday, a day after the series was released on Netflix, Zari took her Instagram and Facebook to mock Fantana for wearing Brazilian Butt Lifts.
Fantana responded, saying Zari wears fake designers, she has a sex tape on the internet and she is married to a high school boy.
Meanwhile, at the end of episode nine, which is the last in season two, Platnumz meets both Zari and Fantan separately.
Zari forgives him and he kissed Fantana goodbye.
Zari Hassan and Shakib Lutaaya got married in April in a private ceremony held in South Africa.