"We now have no class, no appetite and can't sleep well, as a result we can't live a normal life," Miss Geng wrote.
The agency yesterday refused to say if the agent was one of the two independent agents believed to be linked to all the cases because the investigation was still ongoing.
Miss Geng and her twin sister, Sixia, who was also found with altered educational certificates, obtained their New Zealand student visas after their application for Australian visas was turned down.
"We chose the agent only because her company gave us a 100 per cent assurance of getting a visa," said Miss Geng in Mandarin.
"We gave her our documents, which were all authentic, but were shocked when we were told that she had changed them for our application."
The sisters sat the national college entrance exam at the age of 15 and graduated from Jilin Art School, majoring in dance, at 17.
"I think the agent changed the dates on our graduation certificate because it is not usual for students in China to graduate at such a young age," Miss Geng said.
They have not been able to contact the agent since July, when the fraud was uncovered.
Another student, 21-year-old Benson Li, said agents at the same centre in Jilin got him a New Zealand visa after failing twice to get visas for him to study in the United States and Australia.
"I didn't even want to come to New Zealand, but was told it was the only place where the visa was easy to get," Mr Li said.
A New Zealand immigration adviser acting for 20-year-old Guangdi Liu, also from Jilin, said many of the students were "victims" and not perpetrators of the fraud.
The adviser, who did not want to be named, said the Chinese agency lured the students with a promise of "no visa, no fee" and included false documents and fake bank statements to back the applications without the clients' knowledge.
"Original documents are handed to the agent, but in order to strengthen the application the documents are amended or substituted to show higher educational qualifications and bigger bank accounts," he said.
An immigration officer in Beijing told the Herald in July that students who failed to gain visas elsewhere were channelled towards New Zealand after Immigration New Zealand relaxed its risk-profiling rules at its Beijing office.
The agency stopped verifying most academic qualifications gained in China last year, making it a "magnet" for fraudulent applications.
Of the students who entered New Zealand on fraudulently obtained visas, 10 were deported and 15 left voluntarily.
A further 159 are unlawfully here and 61 have been granted further visas.
Immigration said its compliance officers and Labour inspectors were targeting "high risk" private training establishments suspected of having breached the Education or Immigration Acts in an ongoing investigation.
"As the investigation is ongoing, it is not possible to discuss details of agents who may or may not have been investigated," said agency spokesman Marc Piercey.
Mr Piercey said Sining Geng's appeal against deportation was still being considered and a new student visa application was being processed for her sister.
"Both these applications are awaiting verification of the documentation provided."
Beijing student visa scam
300 visas found containing fraud
245 students entered New Zealand
159 here unlawfully
61 granted further visas
25 deported or left the country
2 independent agents linked to all cases
Source: Immigration New Zealand/Tertiary Education Minister Steven Joyce
