The South African Embassy has been inundated with calls from confused travellers after the country made changes to its visa rules.
From 16 January, New Zealanders will need a three-month holiday visa in order to visit South Africa, the country's government has said.
The changes are a retaliation, after New Zealand dropped visa-free travel for South Africans.
Air New Zealand has warned travellers who would arrive before that date but would not leave until after that they would be unable to leave the country without the visa.
Flights back to New Zealand before the change were already almost fully booked.
Former Auckland deputy mayor Penny Hulse was expecting to fly to South Africa on 29 December and return on 17 January.
She said Air NZ would not let her fly without the visa and travellers would have to travel to Wellington to get the visa, which could be was costly and difficult at this time of year.
"It's thrown everything sideways, and the difficulty is not necessarily the visa but the fact that we have to fly to Wellington and obtain a visa face to face.
"And trying to do that a week before Christmas is chaos."
However, South Africa's High Commissioner to New Zealand Zodwa Lallie said the country's Home Office would clarify early next week which travellers needed to obtain a visa.
"If we state that [the visa is required] on and after the 16th of January, then one would not expect that on your return you'd be expected to produce a document you were not required to have before you leave New Zealand," she said.
"That would be unreasonable in my view."
Ms Lallie said the January date was decided to avoid disrupting people's Christmas plans.