I love the ability to tap my phone to pass through the subway turnstyle. I linked my Chase Sapphire Preferred card to GPay for this purpose. I saw a sign on the ticket kiosk stating that only Singapore bank credit cards may be used but I ignored it since I wasn't using the kiosk. The day after travel I received a message on my GPay app that my payment was declined. I called Chase who denied that they were the problem. The next day my phone would not open the turnstyle but tapping my CSP card worked fine. later that day I got more messages that the card failed.
Can I use my CSP on their subway? How do I clear these charges?