obsolete for those ones who are on a budget, elite visa has no taxes if u bring money from abroad and this seems fit op perfectly... If I had money I'd go 100% on elite
Cancelled means you didn't fill the application properly, wrote something incorrectly or didn't include the required documents. It's hard to understand what happened from your post
If they didn't reply you then it means they can't reschedule. By claiming u got an urgent meeting in Thailand is going to bring your application to get rejected, u can't conduct any sort of physical business in Thailand, even with the DTV. Is that meeting more important than 10k spent for the application? If yes then go for it and then apply again in Vietnam otherwise u just move your meeting