Welcome to AOL ... they were equally as inept with my in-laws, who needed to change their account details because they had had their credit card stolen so needed to register a new card with AOL for payment. They ended up with two entirely separate accounts with AOL and AOL sending them red bills on the first one as they could no longer collect payment on the cancelled card.
So far as I can tell, AOL only collects payment on a card; you can't arrange a direct debit. I make it a personal rule in my financial affairs not to deal with companies that insist on you signing up to recurring card payments as you have no control subsequently over those payments and you are effectively at the mercy of the service provider, which in AOL's case I think is a very bad thing. With a Direct Debit, you always have the option of going direct to your bank to cancel it and merely informing the service provider afterwards. Your bank cannot cancel a credit/debit card mandate.