I have a multi-trip on a single ticket (LHR-SIN-DPS-SIN-LHR). There is a week between landing in SIN and departing to DPS.

My SIN-DPS flight is in the evening and I need to move it to the morning.

I tried calling SQ and I was told to call my travel agent (eBookers). They told me my ticket could not be changed.

Is it worth me talking to the SQ desk on arrival at SIN and seeing if they can do anything, or travelling to SIN early on the day of the planned departure and seeing if they can bump us to an earlier flight? Or waste of time? It's business class, if that makes a difference...