How do I complain about an UPI transaction on NPCI?

To complain about a UPI transaction on NPCI, visit the official NPCI website. Navigate to the 'What we do' tab, select 'UPI', and then click 'Dispute Redressal Mechanism'. Scroll down to the 'Complaint' section, choose 'Transaction', and select the nature of your complaint. Provide details like the transaction ID, bank name, amount, date, and email ID before clicking 'Submit'.