We were booked in I class on SQ632 connecting in BKK to TG970 to ZRH. The flight was scheduled to depart SIN at 20:40. We were at the gate around 20:05 (the monitors already showing "gate closing"), when the gate staff informed us, that the aircraft has to be exchanged and that we will not make our connection. But they said no problem, just go back to the SKL and they will rebook you on our direct flight. As far so good. When we arrived at the lounge booking desk, they blantly refused to rebook us, first claiming they cannot do it since it is a award ticket, then that there is no availibility (I cheked online and the flight was wide open), finally they tried to put us on the LH flight, but LH refused that. Eventhough they had told us, that we have to get rebooked neither the lounge staff nor the supervisor rebooked us. So we had to take our original flight and barely made the connection, but only due to the direct transfer we got, due to our insistance. The other reason why they switched the planes so fast was, that there was a pemier minister onboard. Anyhow this was again a foe me typical example of SQ's nonexiting customer service, their lack of taking responsibility and not standing to their word. IMHO if they clearly tell us, that they will rebook us, it is just ridiculous to deny it 10 minutes later and involve us in 90 minutes of discussions, especially since the had the chance to find win-win situation! In Englisch, weil ich keine Lust hatte es zu übersetzen, hatte es halt in Englisch auf ft gepostet.