Mr Tankersley said: "What happened to Mary isn't new but it highlights the bullying and hate that transgender New Zealanders face all too often. I urge Farmers to investigate this incident and to train their staff to treat every customer with respect and dignity."
"If we see anyone being bullied and shamed: I hope other shoppers will stand alongside them and let the person humiliating them know that their behaviour is totally out of line and won't be accepted."
He added anyone seeing someone being bullied and shamed should take a stand.
Mrs Haddock-Staniland says the Farmers assistant was "rude from the start", laughed at her and repeated her slurs to other customers.
"The way she singled me out made me feel as if I shouldn't be there - she kept on laughing at me, even as I tried to ask her what the problem was.
"I'm disgusted, I'm a strong transgender advocate in the community. I'm furious that I and my best friend have been made to feel uncomfortable."
Mrs Haddock-Staniland, who left without buying the shorts, says Farmers should be accountable because the way she was treated was not okay. While the assistant was entitled to her opinion, the customer should come first.
"She shouldn't be working there if she is not okay dealing with people like me.
"As a trans person, mild humiliation is sadly par for the course when shopping but this was on another level. I am a customer like any other, there to shop, not to be laughed at, not served and described loudly to other customers in a derogatory way."
Her friend, Mitchell Harvey, was equally disgusted.
"Mary, well she is a beautiful woman. Never in my life have I ever been put into a situation like that."
He says the assistant took other customers to the other end of the changing room and the incident had left him "feeling sick to the stomach".
Farmers managing director and chief executive Rod McDermott says the company has launched an investigation into the allegations.
"As a company, we teach our staff that all customers are to be treated with respect and we take very seriously any claim that this has happened. We would of course be happy to speak directly with Mary should she wish."
Farmers corporate relations manager Nikki Newton-Cross said the company was very supportive of the transgender community and apologised for the treatment of Mrs Haddock-Staniland and her friend.
She said a senior executive is currently in store speaking to the Botany staff.
Mrs Haddock-Staniland was not prepared to speak to Farmers "right now" but said she would be willing to talk to them at a later stage.
Human Rights Commissioner Richard Tankersley praised Mrs Haddock-Staniland for going public after being humiliated and ridiculed.
"What happened to Mary isn't new but it highlights the bullying and hate that transgender New Zealanders face all too often," he said.
"I urge Farmers to investigate this incident and to train their staff to treat every customer with respect and dignity.
"If we see anyone being bullied and shamed: I hope other shoppers will stand alongside them and let the person humiliating them know that their behaviour is totally out of line and won't be accepted."
He added anyone seeing someone being bullied and shamed should take a stand.
"I hope other shoppers will stand alongside them and let the person humiliating them know that their behaviour is totally out of line and won't be accepted."
Farmers posted a message on Facebook this afternoon saying it was taking the matter "very seriously" and were investigating it "as we speak".
"Farmers is very supportive of the transgender community, in fact just last week we had Attitude TV filming a piece in one of our stores where we provided a makeover transformation to a young transgender customer.
"Our staff (also transgender) was the beauty consultant. Farmers does not discriminate against anyone and welcomes all people into our stores. We apologise to Mitchell Harvey and best friend Mary Haddock-Staniland for the experience they had. Our senior executive is currently in store speaking to our Botany staff."
Mrs Haddock-Staniland also posted a message to her Facebook page following the incident.
She said she would be lying if she said "I wasn't hurt or upset at the woman's behaviour".
"But at the end of the day, everyone has a different perspective, and I single handily can't change everyone's opinion of "people like me" but I'm going to try my best. Thank you so much for all your lovely messages both privately & publicly. .. Arohanui x"
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