Client, AP, has already approved the proof.
Normally, the client sends the artwork to us firstly, next we will send to you. So, next time you can feel free to ask us about it when delay.
In terms of formal letter, we understand your situation and still await your response due to the fact that all documents will be issued by internal applications. Once we receive the letter, we will process to buying team to edit your magazine name in the applications taking around 2-3 working days.
We look forward to hearing from you as soon as possible.