This happens when you print at one of the SB or DPL Epson print stations. When you select an Epson printer, it talks to PaperCut to confirm it's on/active, and PaperCut counts that as a print. But PaperCut also knows it isn't really a print as it has no page size associated with it, and instantly refunds the job and credits your account!
(Occasionally PaperCut will not automatically refund these "Supplies Level" checks. If that happens, go ahead and request a refund the way you normally would. See THIS KB article if you need help with that.)