It's been my experience that transactions that fail on the PSN website often work when being placed through the console itself. However since you said it fails with the same error on your console, the next step would be to contact the customer service department of your credit card issuer.
Sony uses some fairly strict payment method authentication because they instantly deliver non-tangible products that aren't expensive enough to warrant serious legal pursuit of someone in the case of fraud. As a result, if the address and name info they have for you isn't 100% identical to what your card issuer has, it won't go through. Unfortunately they give the same vague error message when a transaction fails no matter the reason; even if the transaction is explicitly being declined because of an info mismatch the message will still make it sound like a temporary problem and tell you to just try again later.
Your card issuer can quickly look up your transaction history and tell you whether or not the actual purchase was ever submitted by Sony, and if it has, they can tell you exactly what Sony said your info should be. When I was experiencing the same issue recently it turned out that the mistake was actually on the part of my card issuer; they had "Apt #xxx" for my apartment number in my street address while Sony only had "Apt xxx". That one-character mismatch was enough for the transaction to fail. My card issuer removed the '#' from my profile with them and the problem was instantly corrected.
Now if it turns out that your card issuer has no record of the transaction even being submitted it indicates the error is internal to Sony's store and you should contact PSN customer service. However since the first thing they'll likely suggest is to call your credit card company and do what I detailed above, at least you'll be able to tell them you already have and they had no record of the transaction.