1. Try not to take it out on front-line employees (your Starbucks employee) personally. Tho I have no similar reservations on owners and managers.

2. Usually DCC not a choice - see St Regis Shenzhen terminal for instance. In that case the merchant bank (Bank of China) even locked the VOID button to try to lock in their gains.

3. If you are asked whether to DCC or not before given final slip to sign, you might be getting a choice about DCC. Tell the staff no DCC and sign, keep a copy of merchant slip (or your slip if carbon) and check transaction when you return home.

3a. If you are simply presented with a "Mark[X] Transaction Currency" slip but the merchant has already printed his slip, you've been DCCed and should void the transaction right away and present alternate payment.

4. If void not possible/not performed, take photo of merchant slip (if thermal) or keep your copy of slip (if carbon) and raise Reason Code 76 with your bank. Do not accept out-of-pocket compensation from bank (Schwab tries to do this), make them follow through and dispute the merchant bank