You can reach a support executive at Zerodha via call in a few minutes. If you call from an unregistered number, you need to enter the support code.
You can call 080 4718 1888 or 080 4718 1999 Monday to Friday from 8:30 AM - 5:00 PM for assistance on-call or visit support.zerodha.com to learn FAQs and create a ticket for further assistance.