Update 2: The issue appears to be resolved. Thanks!
Apparently there's been some kind of change (between now and the end of September) and Riot no longer accepts (or PayPal no longer allows) instant bank transfers from PayPal? This is really unfortunate, since I do not own a credit card - so basically, I can no longer purchase RP to buy skins.
May I ask why the change took place?
I know there are other payment methods - but for one reason or another, assume they are unavailable to me.
Hopefully it's some kind of error. I can't imagine why bank transfers would no longer be allowed.
Update 1: This is the message I get from PayPal. After speaking to Ames, it may be something on their end. Thanks for looking into it, Ames!
I select Purchase RP -> PayPal -> Sign in -> Change Payment Method, and then Credit Card is the only option. When I click on "Why don't I see my other payment methods", it gives me this:
Bank account (Instant transfer): MyBank Chequing (Confirmed) x-5555
To help protect our members against fraud, we review every transaction and may block a payment method when we see a potential risk. Although our fraud measures occasionally block a legitimate payment, to maintain overall security, we don't overturn any decisions about an individual transaction.