It supposed to be easy to exchange money anywhere you go. However China is different. Yes, you can exchange foreign currency to Chinese yuan but when you wish to exchange Chinese yuan to foreign currency then there is a problem. In big cities they know procedure and they have popular foreign currencies without appointment. With small cities however is different. First of all you need to make an appointment to reserve the currency, then you can exchange only 500 USD a day/person and the most stuff in the bank of small town would not be sure about the procedure of dealing with foreigner. They are not sure if the foreigners can actually exchange the money and if they have checked it out after making you wait for more than couple of hours, then they would try to figure it out which one in your passport is your name and where actually are you come from. So whole procedure of exchanging 500 USD can take up to 3-4h. And I don’t recommend to simply stay calm. Shout, complain leave and they will call you saying sorry many time, begging you to come back and things will go faster. Welcome to China.