(1) The debtor shall not be liable under a credit-token agreement for use made of the credit-token by any person unless the debtor had previously accepted the credit-token, or the use constituted an acceptance of it by him.
(2) The debtor accepts a credit-token when-
(b) a receipt for it is signed, or
(c) it is first used,
either by the debtor himself or by a person who, pursuant to the agreement, is authorised by him to use it.