(a) must deliver the documents to the drawee on acceptance of the draft if it is payable more than three days after presentment; otherwise, only on payment; and
(b) upon dishonor, either in the case of presentment for acceptance or presentment for payment, may seek and follow instructions from any referee in case of need designated in the draft or if the presenting bank does not choose to utilize his services it must use diligence and good faith to ascertain the reason for dishonor, must notify its transferor of the dishonor and of the results of its effort to ascertain the reasons therefor and must request instructions. But the presenting bank is under no obligation with respect to goods represented by the documents except to follow any reasonable instructions seasonably received; it has a right to reimbursement for any expense incurred in following instructions and to prepayment of or indemnity for such expenses.