Interpersonal communication problem

This incident happened in the previous company where I worked as an intern - there was a misunderstanding between the CEO of a company, his secretary, and myself, who at that time was a junior travel consultant.

Most of the time, agencies like the one I worked in receives calls from secretaries to settle travel arrangements. However, occasions whereby the CEO themselves directly calling the agency to settle and or alter their travel arrangements is not unheard of.

Which was what happened in this case. The CEO himself called me and made a special request to book a seat in the business class for a two hour flight, which was against the company policy. On top of that, the difference in prices were paid through his personal credit card - a crucial piece of information that was lost in the process of communication between the secretary and her CEO. His secretary singled me out for I was the one who completed the transaction, and immediately set out to confront me harshly regarding the issue. She did not allow me to explain myself thus forcing me to sit through the whole ordeal.

Looking back upon this incident, I have concluded that one possible root cause for this unfavorable outcome is due to the fact that there was a communication break down on their end of the company. A mistake that the secretary had assumed the agency had been responsible for. I felt terrible for having been treated harshly despite the fact that the issue was not caused by my negligence.