Not all schools in Limpopo had received textbooks by Thursday, despite the education department's claim that it had met its deadline, said the SA Principals' Association.
"What do they [education department] mean they met their deadline? Even if one school didn't receive textbooks it is one too many," said the association's deputy president Ngoako Rapaledi.
"They can't say that they met their deadline. I am on my way to a school where they have to still deliver textbooks. That same truck has more deliveries to do for this morning. What deadline?" he asked.
The department had an agreement with rights organisation Section 27 that all schools in the province would receive textbooks by Wednesday night.
Earlier, education department spokeswoman Hope Mokgatlhe said that by Wednesday night all the textbooks had left the warehouse.
"If people say we have not met our deadlines, they must bring evidence. There might be a few schools that have not received their books because there was no one at the yard, but the books are there."
Section 27 spokesman Mark Heywood said it had only anecdotal reports from the ground, but expected to have a full report from the department at 9am.
"There certainly was a big effort, and I think many schools will have their books this morning," Heywood said.
"However, we have received contradictory reports as well, therefore we call for an independent verification of the report. There could be some bad people in the department that will lie and can't be trusted."
The Democratic Alliance (DA) in Limpopo was closely monitoring the delivery.
"I can say with 100 percent certainty that the department didn't meet their deadline," said DA education spokeswoman Desiree van der Walt.
"Many teachers waited 'til late last night and previous nights in unsafe conditions for textbooks to be delivered and they were not delivered.
"Late Wednesday night, there were still warehouses with pallets of thousands of textbooks that needed to be delivered."
Beeld newspaper reported on Thursday that Van der Walt had been threatened with arrest when she wanted to move books scheduled for destruction.
SA Democratic Teachers' Union provincial secretary Matome Raphasha said intervention was needed in the textbook crisis.
"We have seen more problems than solutions," he said.
Workers at a private warehouse which was tasked with textbook delivery, said more textbooks were delivered on Wednesday and had yet to be packaged and distributed to schools.
The department of basic education was initially ordered in May to provide Limpopo schools with textbooks by June 15.
The High Court in Pretoria ruled in May that the department's failure to provide textbooks violated the Constitution.
Section 27, which brought the application, met the department after the first deadline expired, and it was decided that delivery of the textbooks be completed by Wednesday.