The school's owner, Anahit Grigoryan, said on Friday that the city never notified her and other campus officials that an order had even been presented to the judge.
As far as Grigoryan knew, she said the kindergarten-to-12th grade school was scheduled to reopen Tuesday for the first day of classes.
"It's just illegal," Grigoryan said, adding that she would be consulting her attorney.
Still, city officials contend school administrators have failed to obtain zoning permits for operations and parking, as well as showing compliance with building codes.
The city claims school administrators also failed to meet several healthy and safety codes, including for the subterranean garage being used as storage and a playground area.
According to the complaint, the school lacks adequate parking, needs a permit to run a school in the zoning area, and must change its current retail and office permit to one needed to operate a school campus.
While school has corrected some of the code concerns in the past, Howard said many remain unchanged.
The school was forced to move out of its Foothill Boulevard site in February after code investigators said the building wasn't properly retrofitted to house students and it didn't acquire the necessary permits.
Grigoryan sued the city and won the case, in which a Los Angeles Superior Court judge allowed them to operate while school operators worked out the permit issues.
"They took care of some of the violations, but there is a significant number that still exits," Howard said.
A hearing regarding the temporary restraining order is scheduled Sept. 17 in Los Angeles County Superior Court in Glendale.
School administrators must demonstrate during the hearing why the judge shouldn't issue a preliminary injunction against the school, which would be the first step toward a permanent injunction.