Is there a free or low charge if you call SG? I couldn't find any free app!

Hello, I have a client located in SG and he is asking about a process in their bank. Is there a free or low charge if you call SG? I tried to find an app, I couldn't find any free one.

I tried sending an email sa bank pero nagbounce back ung email ko.

I have a landline with Globe but their CS is still close to confirm if the 1800 number is free or how much is the charge if the SG number will be called directly. Thank you to those who will answer.