Bantleman was charged with sexually abusing children at a private school in Jakarta in 2013.
Bantleman's brother says his family has been struggling after being caught off guard by the news.
He told Radio Humber having to go back to prison weighs heavy on Neil.
"It's restarting the machine. We thought there were better times ahead," said Guy Bantleman.
He said his family will be working closely with the Canadian government and Toronto legal teams to bring forward Neil's freedom.
Canadian Foreign Affairs Minister Stephane Dion says the government is "deeply disturbed" by the court's decision.
Neil's brother also says that working with the Indonesian government has been incredibly challenging.
" I don't believe the Indonesian judiciary can wrap their heads around the notion that he's innocent," he said.
"Dates and times seem very fluid. Days and weeks go by. That's been very frustrating."
Guy expects he will be able to speak with his brother in two weeks.