He had been sentenced in 2017 to 13 years in prison for the 2013 murder of his partner Reeva Steenkamp.
Pistorius must continue to serve his sentence until a new parole hearing next year.
Some in Pretoria backed the decision by the prison board.
"Reeva will never come back. Her parents will never have peace, never and I also think, if it was my kid on that situation, I would want that person dead or be in jail," Lebohang Mokoena shared.
"I still feel he needs to sit more in prison and serve more in prison so that the rest could learn. Because now if they are releasing people like this on a faster note, it wouldn't be fair enough for for for South Africans," Leonard Tshweo reckoned.
"I feel like he should serve more time because he is not ready to face the world," Precious Matumba said.
"You know, now, most most of the people are dying. Most women are been killed everyday. So the justice system is failing us every time."
The 36-year-old has always claimed he shot his girlfriend on Valentine's Day in error after mistaking her for a dangerous intruder.
Steenkamp's parents still believe he is lying and opposed Pistorius' application for parole.