The centre re-opened after its suspension on the condition that the owner and manager, Pauline Murphy, stayed away.
In some of the complaints former staff said the manager would grab children's wrists and yank them so hard staff were worried they would be dislocated.
One former teacher, who has not been named, said Pauline Murphy would threaten staff with warnings for comforting or cuddling hurt children.
She said Murphy would also use dangerous methods to treat children for headlice.
"On some occasions many of us were witness to Pauline pouring disinfectant over children's heads as they stood on a small stool and have their heads over the basin to treat them for headlice."
She said teachers would try to complain to the Ministry of Education (MOE), but confronted a system that demanded the initial complaint must be dealt with through the internal procedure first.
In this case the process was to complain to the owner and manager at the centre - the very woman they wanted to raise concerns about.
"Many teachers wanted to say something but as the complaints procedure was to in the first instance go to the centre manager, they couldn't go to Pauline as she just swept complaints under the rug and then you were bullied and your job threatened for doing so.
"If you phone MOE with a complaint, they say to you, that you must follow the centre's complaints procedure.
"At Pitter Patter Education centre, the complaints procedure was to in the first instance go to the centre manager.
"If you did, then you were reprimanded and nothing happened to your complaint. MOE were not interested in your complaint if you had not followed this."
The former Pitter Patter staff member said if they spoke out directly, Pauline Murphy would threaten their jobs and had taken other staff to the teaching council for complaining.
And when complaints did get through to the ministry, she said their investigations weren't thorough.
"I remember one day after the allegation came in from ministry about children being locked in the bedroom for disciplinary purposes.
"Not once were the teachers interviewed by MOE about these allegations and at the next staff meeting after Pauline was seemingly cleared of these allegations it was a real witch hunt as to who had reported it to MOE."
She did not understand how the ministry could investigate a complaint without talking to other staff members, she said.
The manager from the centre, Pauline Murphy, has not responded to repeated requests for comment.
Another former teacher said there was always the risk of losing your job, or legal action if you did speak out.
"If you went to the extreme to voice what happened at Pitter Patter and the truth about Pauline she would then go out of her way to come after you, making promise of her constant threats with using the teachers council and going after your practising certificate."
One parent showed the response she got to a complaint raised with the ministry, in which a senior education adviser, again referred her complaint straight back to Pitter Patter's management.
The email added that the ministry expected it to be handled professionally and wouldn't affect her child's relationship with staff.
"If after following the complaints procedure, you feel your concerns have not been addressed, then please contact me again and I will follow up with the service."
The Ministry of Education's acting deputy secretary of sector enablement and support Jann Marshall said when they receive a complaint they always asked if the complainant had followed the services complaints process.
"Regardless of the answer, we can, and often will, investigate complaints.
"We may refer the complainant back to the service's own complaints process but only if appropriate, for example if it's an employment concern or a concern from a parent about an administrative matter.
"If the allegations are serious or referring back to the service creates a risk to the complainant or children, we don't."
She said in any investigation they speak to as many relevant people as possible to gather information and they rely on people speaking up when they see something of concern.
However, Marshall said the ministry continued to improve their processes and learn from current and previous investigations.
"Like all organisations, we continue to look to improve our processes and the complaints process is no different. "
The investigation is continuing and complaints have been passed onto the police and the Teaching Council.
• This story is not connected to the Auckland child care centres with the same name.
