Ms A also did not take Mrs B's client history into account, Mr Hill said.
He said Mrs B found the treatment to "be very forceable and painful".
"The massage was of a very violent nature and painful contortion style... she continued pushing, pulling limbs, very forceful pressure on the back of my neck and the front of my throat hurt, she climbed onto my back on two or three occasions; digging her knees into my back," Mrs B said.
However Ms A said her hands and feet were always supporting her own weight.
She said she assumed Mrs B was aware of the process involved in a Tui Na massage when she purchased the voucher.
Mrs B said following the treatment she had a bad night's sleep, and had a sore back, neck and shoulders in the days following the massage. She also complained of a headache.
A sign outside the therapist's treatment room, said "Acupuncture Clinic" and "free ACC", however Ms A was renting a room at the clinic, and therefore the clinic's ACC accreditation did not extend to her.
Mr Hill said given the nature of the treatment, Ms A should have clearly explained that a Tui Na massage was a deep tissue massage and could potentially be uncomfortable.
Mr Hill recommended that Ms A provide a written apology to Mrs B, and offer her a refund.
As well as this, Mr Hill said Ms A should discuss and review with a peer or colleague, her initial assessment of clients, as well as indicate to clients that she is not ACC accredited.
A spokeswoman for ACC said massage therapists were not considered to be registered health professionals and were not accredited by ACC.
However, acupuncturists could be ACC accredited, which was why there may have been a sign near the therapist's treatment room.
"I'd suggest in that situation that clearly people are thinking this looks good because there is a sign here that says ACC, they should check with the manager of the clinic and get a pretty clear sense of what that accreditation is for."
Manager of environmental health for Auckland Council Mervyn Chetty said the council did not require massage clinics to be registered to operate.
"However, they must meet all zoning and building requirements, and be maintained to an acceptable standard.
"If a premises is operating other health services such as pedicure or manicure, the premise and operator will need to be registered with council and display a current health licence."
Mr Chetty said Massage New Zealand promoted best practice in massage.
Anyone thinking of getting a massage could check the Massage New Zealand website to see if the therapist was recognised by them.