The best thing is to find a friend or relative you can trust at a bank. They can often get the "mid-rate", which is than the bid or ask on the interbank rate depending on whether you are buying or selling.

As for myself, when I need to move a large sum from Malaysia, I happen to know the head of treasury at one of the large Malaysian banks and just call him. He will simply instruct one of his dealers to give me a good rate.

A Citigold customer is the lowest level of priority banking at Citibank Malaysia. All you need is something like RM200K in FD, which is like SGD80K. Do you really expect priority service with that kind of lowly status? 10 years not withstanding. You need to be on one of the higher tiers or be a private bank customer to enjoy priority rates. Citibank Malaysia is still far superior to OCBC Malaysia, but you need to have significant business with them.