We are sorry to hear about your experience.
Agents are not allowed to discriminate based on race or religion unless it is to comply with the Ethnic Integration Policy which aims to achieve a balanced ethnic mix among the various ethnic communities living in public housing estates.
The CEA requires all estate agents to uphold a high level of conduct and ethics. If you feel you have been aggrieved, you may wish to complain to CEA via the following link: https://www.cea.gov.sg/consumers/complaints/report-a-salesperson-estate-agent
Hope this answers your question.