To be paid out, you must have at least $10 more in eligible earnings than your "Balance to be left in account" (which you choose). For example, if your "Balance to Be Left in Account" is $5.00, you must have at least $15.00 in eligible earnings. Eligible earnings are drinks earned, NOT those given as part of a promotion. Funds added to an account from a credit card are not eligible to be paid to you. Except when specified, funds credited to your account for Special Offers or other Promotions will also not be paid out.
You can read more details about getting paid here.
If you think you should have been paid and weren't, drop Customer Support a note at firstname.lastname@example.org so we can take a closer look.