Request for information on credit hold

Dear When I attempted to utilize my (firm) charge card for a purchase on (date) , I was informed that I would have to speak to the credit office before I could charge any additional purchases to my account. Inasmuch as there were several customers waiting in line in your credit office, I am writing to you instead. Could you please tell me if there is a problem with my account, and, if so, the nature of the problem? I will be looking forward to your prompt reply.