"We're now expecting to know by the end of the week. I'm sure they want rid of the whole thing as well.''
Mr Buitenhuis and his wife Marthie, 47, emigrated from Pretoria to Christchurch six years ago and quickly got full-time work at a local restaurant.
But since applying for permanent residency more than two years ago, Mr Buitenhuis' 130kg bulk has held him back - despite losing 30kg in recent years.
Immigration New Zealand (INZ) rejected his application on May 1, saying his obesity coupled with a knee injury could place too big a strain on the health system.
INZ criteria decrees that an applicant's body mass index (BMI) must be under 35, but Mr Buitenhuis' BMI is 40, which makes him clinically obese.
Mr Buitenhuis said he was "stunned'' by the original decision, and lodged an appeal.
But he and his wife are worried that even if they win their fight to stay they will be financially crippled.
They haven't been allowed to work since May 2 and were forced to leave their Christchurch home and move in with Mr Buitenhuis' sister in Auckland because they couldn't keep up with rent payments.
"I've been fighting like this because I love the place (New Zealand),'' Mr Buitenhuis said.
"We're not allowed to work and sitting around, doing nothing, is really getting to me. You can't do anything. You can't believe how frustrating it is. I need a decision as soon as possible.''
A Facebook campaign has been launched to try to fund their battle.
Ms Kaye has said she is unable to discuss the specifics of the case.