I'm planning to buy some public transport tickets at the post office at the airport; and I am wondering if they accept credit cards or just debit cards and cash.
Also, will they take Euros?
If the post office doesn't accept credit cards, you can buy public transport tickets at BKK customer service points. You will probably see one right in front of you once you leave the baggage claim area. They are very visible. They do accept credit cards. Not sure about EUR though.