While I don't share your level of rage, I've used "Paypal Credit" and BillMeLater (before it became Paypal Credit) accidentally several times.

For a long time I refused to add a bank account to my PayPal account simply so my credit card would be my default payment option. Then BillMeLater had an attractive promotion, so I used it 1x and paid off my balance before it accrued any interest.

Since then, BillMeLater and now PayPal Credit are my default payment options. There's no way to change this, and it's a very consumer-unfriendly practice.

I'm glad they're getting fined, and I sincerely hope this results in their allowing user-defined default payment settings.