If your customers card is declined by Braintree you can look up the code for the reason of the decline.
You should have access to this information in your gateway.
You will looked up the unsuccessful transactions in your account and a note will be next to the transaction’s decline code:
Here is a link to access the codes: https://developer.paypal.com/braintree/articles/control-panel/transactions/declines#code-2046
This link provides more definitions on Braintree decline codes.
If you need additional assistance with a decline please reach out to Braintree directly at: CaterZen@Paypal.com