KC Contractors did not take part in the authority's investigation or respond to requests for documents.
The Employment Relations Authority found a reasonable employer could not have acted in such a way.
KC Contractors did not discuss any concerns with Ms Hansen, did not give her the opportunity to comment and did not genuinely consider her explanation.
The authority said Ms Hansen was distraught when she received the text, her mood and confidence changed, and she was stressed over the loss of wages.
She was awarded 13 weeks' lost wages, amounting to $9282, and $5000 for humiliation, loss of dignity and injury to feelings.
The company was also ordered to pay $1695 costs.