The Contactless Symbol looks like this:
Also, fraudsters cannot re-use the one-time code that secures your payment information because the code is specific to each transaction. Even if they were able to access it, the information would be useless to them.
The process to return an item purchased in-store with Google Pay is the same as if you were returning an item purchased with a physical card. Most merchants require you to have the original receipt along with the payment card used for that transaction. If the merchant asks you to swipe your card, simply hold the back of your phone to the contactless payment terminal. For some returns, you might have to provide the last 4 digits of your digital card number.