Dear Mr. / Ms，
On 14 November I submitted a bill for services rendered to your office at the Lille International Exposition. More than a month has now elapsed without payment or acknowledgment of my bill. Please check this oversight，and remit payment at your earliest convenience. I look forward to future services to your corporation.
Thank you for your prompt attention to this matter.
Yours faithfully
尊敬的先生/小姐，
十一月十四日我向你办公室在Lille国际博览会上提供的服务提交了帐单。一个月过去了你既没有付款也没有认可帐单。请检查这一疏忽并在最方便的时候付款。期望以后还为你公司服务。
谢谢您能对此事尽快重视起来。
你诚挚的
