Ms Sladen spent $20,000 to come to Rotorua and study at Waiariki last year, with the expectation of doing a CAP course at the institute this year.
She has since been added to a waiting list and told she will more than likely have to wait until 2014 before getting on to a two-month CAP course.
Waiariki said they only had 149 places available on their CAP courses this year, which were filled.
They said this was unfortunate for Ms Sladen but it was a matter of first in first served, with Ms Sladen's application for study on a CAP course coming after the 149 available spots were already taken.
Ms Sladen is distraught over the matter saying she was not informed of an exact date to have her application in by.
She said this was not what she was told would happen when attracted to come to New Zealand last year, by an agent working for Waiariki.
"If I was told that I surely would not have come for this programme," she said.
"They are wanting me to wait for one more year. When I am in need they are not willing to help me. But when I offer them money they are happy to take it."
She said if she did not get her nursing registration by August this year she would not be in a position to gain citizenship before her visa ran out.
She said the additional cost of waiting around for a year and paying for renewing of her visa would be about $10,000.
Waiariki said CAP courses were very popular and they could only offer a limited amount each year because of placements in the practical part of the course, such as at the Rotorua Hospital and nursing homes.
This year they have started taking students directly from overseas onto a 2013 Infection Prevention and Control + CAP course.
This means students who have never been to New Zealand or studied at Waiariki will get the opportunity to do their CAP course before other nurses like Ms Sladen.
Waiariki international education director Prabha Ravi said these students, coming over for the first time, were not jumping the queue. She said they simply had their applications in first, for a CAP course, before existing students had got around to it.
"All of these overseas students met the nursing council requirements probably mid to late last year and all received a pre-approval decision letter from nursing council."
Ms Ravi said they would have liked to have given their graduates, like Ms Sladen, a preference but their priority was filling the seats.
"They have to apply quickly. We don't want to lose [any seats] to another provider, that is the business side of it," she said.
"We give place preference to students who have graduated with Waiariki qualifications but there are no guarantees of places."
Ms Ravi said they did not give existing students an exact date to have their applications in by and simply left it up to them to get them in.
She said all those currently on the Waiariki waiting list are in the country.
She said if a student pulled out or a new placement was made, Ms Sladen could get on to the course sooner. Ms Ravi said most polytechs and institutes of technology had a waiting list.
