I recently booked flights with Vietnam Airlines, received the booking reference number, but never any confirmation email. I contacted the Airline and they said the amount (approx A$2,000) was too large for them to process. I broke it up into two lots of $1000, but with the same result and same response. Interestingly enough with the first booking I also tried optiontown upgrades, they had no trouble charging me about $800 (for the non existent flights) which included $23 in bank fees (which I'll never see again). Has anyone else had this problem? I've now booked with Sigapore Airlines and have asked optiontown to immediately refund my money, including the service fee.