To quote some movie character "what we have here is a failure to communicate". I understand how the OP thinks he paid over 30k THB for the Burma trip but he really did not. He forfeited his 23k THB when he cancelled the trip at the last minute. The operator, in trying to keep the customer happy (silly him), said okay, you can join another trip without the forfeit. Here is a Burma trip which would cost you another 7,420 THB. The operator could have just as easily said "Sorry" to the OP or, the cost of the Burma trip is an extra 37k or he could have sold it to someone else. The common practice is that you lose your trip cost on a last minute cancellation. That is why trip insurance is recommended.
Now, about all the other things the OP said went wrong, those are just as believable as what the other pro-AIDC customers have said so everyone can make their own mind up about who is more truthful. I am not sure.