如果公司无法提供现货或服务，应将可以替代的现货或指定产品的进货日期告诉来电者，

If a product or service is unavailable, the caller should be told what possible substitute is available or when the desired item will be back in stock.

银行须在本证中承诺保证在某一时间范围内指定产品的货款能够支付。

In the document, the bank undertakes to guarantee for a certain time span the payment for the specified merchandise.