Postbank seizure?

Hello, I have the following problem: I have a garnishment on my Postbank account. I've now clarified everything with the creditor. He sent a letter of revocation to the post office on July 10, 2024. I called the post office today and spoke to an employee to see if the revocation had arrived yet. The employee told me no, and today is July 17, 2024. My question is, is it even possible for the letter to reach the post office? Sincerely, Heiko