For transaction disputes, please contact UOB Contact Centre at 1800 222 2121 or +65 6222 2121 (if you are calling from overseas) for further assistance. (Note: For any unauthorized transactions, please contact the bank immediately to freeze your card for security reasons. Alternatively, you may block the card immediately via UOB TMRW mobile app. Select the card to block > Settings > Fraud/Lost ). Refer to https://www.uob.com.sg/personal/support/tmrw-user-guide/block-replacecards.page#fraudulentTransact for more details.