We saw dimishing returns from Yahoo Directory years ago.
Rather than cancel our listing, we changed our Credit Card info to a prepaid card with a near zero balance, just to see what would happened.
We never received any correspondence from Yahoo on trying another card, and our listings are still there after a couple of years.
I just checked the Yahoo wallet however, and I see a bunch of unpaid invoices for Yahoo Directory Listings, however.
I beginning to beleive that Yahoo Directory is on auto-pilot. Nobody is maintaining it. Unpaid bills from Yahoo directory is not going to accounts or collections. Its just there to suck in all those automatic payments.