I had to call +Singapore Airlines
the other day to reschedule a ticket. It took 45 minutes, speaking to two people, being put on hold 5 times, and several times requiring the person to repeat themselves due to the poor connections on +Singapore Airlines
side. This was after three scheduled call backs that weren't placed at the right time.
Compare this to calling +Google Australia
to get a power adaptor fixed. The whole device was going to be replaced, and organised in less than 10 minutes.
Conclusion: +Singapore Airlines
should invest in their call centre infrastructure or get a new contractor with better equipment and empower their employees to handle problems more efficiently.
NOTE: In both cases the service by the individuals were good, but I would give it to Google due to the apparent knowledge of the staff of their service and the support on solving issues.