PayPal one-cent scam: what do I do with the penny?

It’s a private individual I’ve never heard of; they referred to a $500.00 payment I made, which I didn’t; and included a phone number which is not a PayPal phone number. They didn’t specifically ask me to do anything, though.

PayPal itself helpfully provides a “Refund” button right next to the transaction; I assume the scammer would like me to click it. That option is obviously incorrect.

ETA:

If I didn’t make it clear before, the email is legitimately from PayPal itself; they’re correctly notifying me of a real transaction. It’s the purpose of the transaction that’s the problem.

Email from PayPal, which is identical to the language that appears next to the transaction in my account:

[redacted] sent you $0.01 USD

Amount
$0.01 USD

Note from [redacted]

Thanks. . Your payment of $499. 99 has been successfully received, and the change has been applied. If this transaction was not made by you, kindly get in touch with PayPal Billing Team [phone redacted]

Transaction date
July 1, 2025

Transaction ID
[redacted]