This is kind of bad advice because unless it double charged (charged both the Ventra and the Contactless card), it is a legitimate transaction. Sure, the card issuer will probably just issue credit and not even charge back the merchant. But the problem is if you have a pattern of doing little chargebacks, what happens when you need to do a "big" chargeback for a legitimate reason? Will the bank help you or will they look at your chargeback history and see all those little chargebacks and start to wonder if something is funny.