Update via ODIN (step by step)
This firmware is for Asia version of Samsung Galaxy Ace S5830 specifically for Singtel network provider in Singapore users but can also be used by nearby South East Asian countries for it has the same firmware build, the only advantages is that, you'll get the Singtel's default CSC file and you will get some issues updating on Kies in your areas.
Disclaimer: i am not responsible if anything happens to your device by following this procedure. Proceed at your own risk. This is not advisable for beginners, for advance users and experts alike use only.
This is a manual method of updating Samsung Galaxy Ace device using Odin multi-downloader program, so you will need Odin multi-downloader program to be able to update your device.