Do Thai People Really Don’t Know?

So my questions is, do Thai people really don’t know? Or they don’t want to tell? Or is it just that they don’t know how to say it in English? Probably I will figure it when I learn to speak Thai fluently. In the meantime I will try to always have battery and internet on my phone.

Withdraw Cash from Thai ATM: Comparison Between 3 Banks

I always prefer to bring cash with me when I travel and exchange it in loco as it is the most convenient way to get the local currency. But sometimes I just can’t organize in time the shipment of several containers with all the money that I usually need. In these cases I rely on my credit card and I found out that there are significant discrepancies among the exchange rates applied by the Thai banks.