This phone number is listed on their official website. Simply call the number and follow the prompts to speak with a customer service representative. How do I speak to Singapore customer service? To reach Singapore customer service directly, you can use the toll-free number. This line is designated for quick connection with their support team.
Source: https://support.google.com/assistant/thread/304956224?hl=en&sjid=17957011778928178325-AP