so you use a car salesman, highly known for the honesty (cough cough) to drive 4 million baht cash (not suspect at all, banks no good) then lose it.... insurance involved?
you are confused
immigration will DEMAND PROOF from you, translated to Thai, certified by MFA, not the other way round, they will not do anything, you will , if you want your extension...
for once, I see thai style better... now they are alone or with 2, tv, playstation, etc... this is not a punishment... shove them in a room with 30 other inmates