I'm now on my second multi-hour attempt to get through to the SQ call centre to book MEL-SIN-MUC (SQ) + MUC-LIS (LH) as a single Star Alliance award redemption (not possible on the website, but individual availability is there). Does anyone know if it is possible (as a workaround for the problems with the call centre) to:

1. Book online as SQ award MEL-SIN-MUC, and then
2. Via chat or email get them to add the *A(LH) award segment MUC-LIS and recalculate the miles (so that the end result is one *A award rather than two separate awards)

Does anyone have experience with this?