I was on SIN-BKK-ZRH on a cheapo J fare. Indicated at check-in in SIN that I would like to upgrade to F in BKK and would like to have a booking for the full-body massage.
TG staff was waiting for me upon arrival in BKK to pick me up and drive me to the ticketing desk. Paid my upfare (26.000 THB) and was then brought to the Spa where they had arranged for my massage. The 346 to ZRH was a 2008 aircraft - no wear & tear, impeccable interior.
^^^