As I am on the road close to 100% of the time, it makes contacting various entities in the United States bit difficult. Starwood has contact centers that deal with SPG issues in Ireland and Singapore as well, but I have found that the folks sitting in the United States are the most competent of them all.
Some countries block Skype and other VOIP access and calling using a landline or cellphone can be very expensive. You could probably send an email request but, if issue needs back and forth communication, it can take quite some time to resolve. My preferred channel of contacting SPG in a situation like this is the Platinum chat.
You can find the link to the chat on the upper right corner under the Customer Service-link. I then opens the actual chat-application window where you should have your name, email address, and the SPG Platinum account number. You can then enter your question to the space below. I always try to be as comprehensive and complete with my question/request, so that the Platinum concierge, dealing with the chat, can start working immediately with my issue without having to clarify several times.