Oh, I forgot, the only probs I have had is with banknotes, they have to be like straight off the printing press. I pay in dollars, can save over 500bht.
Once I paid with 2x20 Dollar bills, refused one, what he pointed out was ridiculous, I said I haven't got another dollar bill, he said then you pay 1000bht. Hmmmm, a nice little earner.
So now when I buy dollars, I leave them and the receipt in their exchange shop envelope, when I get to Laos, I make sure he sees me take them out of the money exchange envelope, because if the refuse any note, I will ask them to write on the envelope what is wrong with it for the exchange shop......😋