This means that the admin has not approved of this expense, and you will need to send a refund to the bank account details provided. The admin will provide a description for the reason of rejecting the expense. If you agree, you will need to send a refund to the bank account details provided.
If you don't agree, speak to the admin, and if the case is that the expense should not be rejected, the admin has the option to cancel the refund request on the admin web interface. In this case, you will be notified by email that the request for refund was cancelled.