How to dispute an unauthorised bank transaction

An unauthorised-transaction dispute needs two parallel actions: stop further access and document why the transaction was not authorised. A clear timeline is more useful than a large unsorted screenshot folder.

What the official sources establish

Bank Negara Malaysia describes the provider-first complaint route and escalation channels. The bank’s security instructions and investigation process apply to the exact account and transaction.

What to check

• Transaction identifier, date, time, amount, channel and recipient are recorded.
• Login, card, device, SIM or credential changes around the event are noted accurately.
• Every call, report, block, password change and response has a timestamp and case number.
• The bank’s written decision and reasons are requested and retained.

A practical way to decide

1. Contact the bank through its official urgent channel and block exposed access.
2. Report the specific unauthorised items and follow official police or NSRC instructions.
3. Send an indexed chronology and copies, keeping the originals.
4. If unresolved, use the bank’s formal complaint process before the applicable external route.

A useful decision rule

Describe facts and actions precisely without guessing how the fraud occurred. Update the bank when new evidence appears and meet every stated deadline.

Common mistake to avoid

Do not disclose passwords, PINs or one-time passwords in a complaint attachment. Redact unrelated transactions and identity numbers unless the official channel requires them.

Keep the evidence

Save the dated product page, quotation or terms you relied on, together with receipts, model or registration numbers and written messages. Public pages and commercial terms can change; recheck the linked official sources before committing money or making a complaint.