Has anyone ever had experience purchasing an SQ ticket on Orbitz, Travelocity, or other airlines' websites (e.g, united.com or aa.com)? I'm wondering how difficult it is to get after-purchase support for date changes, refunds, etc.

Any help would be greatly appreciated - I'm looking at a trip LAX-TPE in J and the SQ website is pulling up a significantly higher rate than any of the aforementioned sites!