Try and do this <THIS IS SERIOUS STUFF AND MAY GET THE CHEATER INTO A LOT OF TROUBLE>:
1. Make police report -- attention to commercial crimes unit.
2. In the report, state that you have been a victim of an internet sales scam. Give details about the transaction in your report, especially regarding name, address, method of dealing, bank account, mobile number etc etc.
3. Take the police report to Maybank. Tell them you suspect scammer is using Maybank account to conduct illegal activities i.e. cheating people.

Hopefully, there will be stern action taken, which may include suspension of account, arrest etc.