Just to share a data point. Needed to change the destination of a simple SIN-XXX ticket where old and new destination are in the same country. One way Saver Biz redemption, only booked two weeks ago (in Dez) and I wanted to do it online as it should have been straight forward.

Tried app and website and even it recognized the change was free of charge and there was saver space to the new destination (no change in taxes/ fees or miles), the "computer said no" for whatever reason. If even such simple changes aren't possible online then I'm not surprised the contact centers are overloaded.

Called SG number, on hold for about 58mins, got agent who sighed when I told her the website can't complete the change and then she did it efficiently within 5mins including waitlisting a second flight (after confirming & reissuing first one) for the same day that has better timing, but only Biz saver waitlist for now.

Tried the chat bot in between and didn't even manage to get into the queue. Ohh this was weekday SG morning time (10:30amish). YMMV.