Accepting payment for bitcoins online: What types of payment "cards" or epayments are non-refundable?
Western union online money in minutes. The client pays western union with their credit card, the client send you the mtcn, you pick up the funds. Pretty Much Irreversible.

Have you looked in to Green Dot Money Pak?
While not technically for payment processing, it is possible to send these to a merchant and they are non-refundable. FYI they are tracked by the federal government. Also always get a copy of their receipt and a signed waiver for anyone purchasing anything from you with a money pak.

There's a few companies that offer money pak conversion services or you could get a re-loadable card.

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