CV writing service recommendations

Write it yourself.
Apart from being honest to you potential future employers, learning the skills required will improve your personal skill set.
Loads of instructional material on the internet.

............ and you save cash.

I have never heard of such a service in Singapore.
There also isn't a "Singaporean" style for writing CVs - the country has so many cultures and international companies that no common CV format emerged.
It is best to customize your CV for each place you apply at, and use their preferred format if possible (often that from the country of the company's origin, but personal preferences of the hiring manager and HR also play a role).
Differently from Europe, connections and personal contacts are far more important than a written application - so you basically must be in the country and network furiously to have a better chance.

In international companies, important hiring decisions are often not made in Singapore. So, in these cases, you're better advised to reach out to the decision-making departments abroad (e.g. at the company's headquarter).

Thank you Beppi for your detailed reply, it has given me some ideas for my next application.
I personally am finding it extremely difficult obtaining an interview in Singapore even for the jobs where I have matching experience and qualifications for the job ,again I agree with the Networking reference,recommendations by colleague or friend to the hiring manager are a great way to open doors,even if it is just for a chat.

Welshneil wrote:

I personally am finding it extremely difficult obtaining an interview in Singapore even for the jobs where I have matching experience and qualifications for the job.

Singapore employers are known to almost never interview somebody who is not already in the country. (And even if, they don't pay for travel to an interview.)
That's why I mentioned above you need to be physically here to increase your chances.
Alternatively, you could arrange a trip beforehand and mention in your application "I will be in Singapore from XX to YY and that would be a good opportunity for a more detailed discussion."