英语短文改错！！！

英语短文改错！！！

请不要把合同文件放到这里，尤其适用翻译器做出来的。很多专业的格式和说法它不知道我也不知道。至于““sirs”是什么东东？”这个问题他好像是指工程师。 大致改了一下。
Dear Sirs,
It is regretful that there have been no news from you at all about your letter of credit which should have reached us before september 2nd, as prescribed in the contract. We are unsatisfied because you took no notice of our August 5th's letter reminding you for the situation.
you may recall that the same thing had happened during the execution of contract no.4567 we signed with you last year...please note that unless a satisfing settlement has assured this time, we shall be compelled to stop make any new business with you.
we think that we have clearly informed you about the importance of this matter and hope to see your response quickly.
your sincerely

错的有点小多……
第一个“sirs”是什么东东？这就错了~~