The France-based midfielder was left out of the squad announced by the head coach before CAF postponed the Africa Cup of Nations qualifiers due to the coronavirus pandemic.
Zungu took his anger at being left out to social media after one of his fans asked what his feelings were about being sidelined from the national team.
"My manager and my family asked me not to be open about the situation with Bafana on social media and stuff," said Zungu on Instagram.
"What I can say is I am angry. I will speak Zulu so that my manager won't understand it. [Speaks Zulu, translated here] My manager won't understand because once he does, he will send me a message and reprimand me.
"This issue has made me angry, I am not alright. I went to AFCON carrying a knee injury and feeling pain but I went there guys. I gave out all from my heart. I gave all for Bafana.
"Today they don't call me. They don't call me and I am enjoying my best form as always. This thing hurt me in my heart but it's okay."