How can we improve WHMCS?

Using the GoCardless module, if a payment fails for one of these three reasons:

insufficient_funds
refer_to_payer
bank_account_transferred

The WHMCS software will automatically retry payment capture, no matter what. There's no way to block this behavior at all, because the developers didn't think that anyone would want that. However in the US (and other territories as well) GoCardless charges you each time a payment fails. So if a customer never puts money in the account, you get charged in a loop every few days, because WHMCS just keeps retrying. WHMCS support refuses to acknowledge this OBVIOUS flaw in their system and put in a way to modify this behavior.

There needs to be a way to stop automatic re-processing when a payment fails. What SHOULD happen is similar to what happens with Stripe, where WHMCS receives the notification from GC that a payment failed and stop doing anything until we have a chance to make contact with the client. This should at least be an option that can be enabled, even if it's not the default behavior.