I am very sorry to hear your plight. You have probably already tried anything I can think of offhand, but just in case...
(1) Perhaps set up a plain old business account at the bank of your choice, then work them up to the web billing thing... Look for one that will lease you a POS, and allow for phone ordering, then move them to web sales (try not to specify any particular product line, or put up a site that sells some kind of physical goods, then once the billing channel is open...)
(2) Contact FirstData and see if you can either work directly with them, or failing that if they could recommend one of their partners to replace iBill.
(3) - variation on (1) - Approach the bank wanting to accept credit card payment for professional services (IT consulting/contract programming/whatever), web billing would be essential because of the many clients you still have in Europe who desire to settle electronically. When you slip your existing operations in, try to describe is as anything but user generated content - "user managed storage" might be a good one, or "web based archival service", or abstract the exact service from the billing and just say "member fees". If they call you on it, just say that you (perhaps on the advice of your accounting staff) have decided to consolidate all billing operations to reduce operational costs and complexity, and if they are no longer interested in skimming your revenue, could they provide a grace period while you transition to another bank that does want your money. Once they see that you are actually conducting business with integrity, and they are not plagued by requests for chargebacks, allegations of fraud, and other hassles usually associated with questionable web businesses, they will probably want to keep your money.
One other thought, the article you linked to mentions that Penthouse bought iBill, then "backed away" from it when they realized the problems... I wonder how you "unbuy" a business. Is there any chance that Penthouse, as owner of iBill, could be vulnerable to litigation? IBill might not be solvent, but Penthouse certainly is, and generally speaking, it is hard to buy a business for it's assets without also taking on the liabilities - they may have an enforcable hold harmless from indemnity clause in the purchase agreement, but then again, they may not.