Payment declined - can't figure out which customer?

I got an email saying a customer's payment method was invalid, it gave me the last 4 digits but I can't find them in my square. 

This was through the square subscription integration. 

Help!? 

Sorry, but since the customer's payment information is not stored at our end, we are unable to verify which customer's payment has been stopped based on the last 4 digits.

There are a total of 9 submissions in this form and I guess you can check individually which payment did not go through via your Square account.

You could reach out to Square Support regarding this issue.