Yes. You can still use it in countries which are still using the old method to process credit card payment.
First name : Jun Han
Last name : John Diew

All the banks in Malaysia are using the "ang moh" format. Chinese always have their surname in the front follows by given name whereas it is the complete opposite for the "ang moh". Even all the airlines are using the same format. It is pretty much the universally adopted name filing format.

By the way, is John Diew Jun Han the name registered in your MyKad and with Public Bank ? Because i know that many Peninsular Malaysian Chinese do not actually have an official English name whereas it is extremely common here in Sabah.