How do I make a 1511CALLBACK call?

ZONE Telecom > Business > 1511CALLBACK
1511CALLBACK for local call:

- Dial 1511 + 65 + Tel No.
- Auto hang up and wait for CallBack
- Answer and you are connected

1511CALLBACK for overseas call:

- Dial 1511 + Country Code + Area Code + Tel No.
- Auto hang up and wait for CallBack
- Answer and you are connected