The owners of Mind Body Spirit Store and Centre in Newmarket said they took a stand as "an act of civil disobedience" by keeping their business open to in-store shopping amid the lockdown.
The store opened to shoppers just before Christmas and opened again for in-person shopping this week.
In a statement to CTV News, the owners, Barb Bushe and Karthik Raj, said in part, "This is of our way of bringing to light what we believe are unfair and arbitrary lockdown measures that are causing great harm and collateral damage to small businesses and our community at large.
We strongly believe that these measures violate the Charter of Rights and Freedoms of all Canadians and are therefore unconstitutional."
The health unit quickly took action, issuing the owners with an order under section 22 of the Ontario Government Health Protection and Promotion Act, which enforces strengthening protections against COVID-19.
York Region's medical officer of health, Dr. Karim Kurji, said complying with public health orders is crucial. "This is not what we expect with respect to the whole community's efforts to getting these levels down."
The spread of COVID-19 has never been greater in Ontario, with more than 3,500 cases reported Thursday and 89 virus-related deaths.
York Region has been among the province's hot spots for COVID-19 cases and was placed in lockdown on Dec. 14..
"We will enforce quite thoroughly if anyone else decided to open in the face of the current rules put forward by the province," Kurji added.
Bylaw officers visited the store to ensure the owners were complying. On Thursday, the store was open, but only for curbside pickup.
Business owners who break the section 22 order could face fines of up to $5,000 a day, while corporations could be fined up to $25,000 a day.
The province-wide lockdown is in place until at least Jan. 23.