It sounds like what you're saying is that when you click the donate link on our site, you are given the option of doing so via a paypal payment. BUT, when you click on the subscribe link on our website the only payment options we give you are via a credit card.
You have a verified PayPal account that is tied directly to your bank account and a pre-paid credit card (yes, we have those in America too) but for whatever reason you are unable to use that same card directly through the site or simply don't want to use it preferring that PayPal take the money from your bank account.
Bottom line - You want to subscribe using your valid PayPal account as your payment method and our site is not giving you the option.
If this is all correct, then we need to get an Admin or at least a SuperMod to check in on this. I just checked and PayPal is the only payment I'm presented with when I click on subscribe and select a subscription level.