我方与法国某客户签订一份以信用证结算的出口合同,收到法方开来的信用证单据要求如 下:“SIGNED COMMERCIAL INVOICE IN 2 COPIES. FULL SET OF CLEAN ON BOARD OCEAN BILL OF LADING MADE OUT TO ORDER MARKED FREIGHT PREPAID IN BLANK ENDORSED. INSURANCE POLICY COVERED ALL RISKS WITH CHINESE INSURANCE COMPANY.”我方在规定时间内制单结汇,但遭到开证银 行拒付,拒付理由如下:商业发票没有法人代表的签名;只提交了一份正本提单;保险单金额与商业发票金额相等。问:开证行的拒付是否有理?为什么?