Turkish Airlines Charged Excessive Baggage Fee on New York-Istanbul Flight

Before my New York to Istanbul flight with THY, I called customer service regarding the baggage procedure. When I arrived at JFK Airport, I was told that the information provided to me was incorrect and that I needed to pay an extra baggage fee. I contacted THY again to explain the situation. They admitted their mistake and advised me to submit a refund request. I did as instructed. Although they initially said the process would be completed within 14 days, it has now been a month with no refund.
Today, I was told that the refund would be processed at an unspecified date. While I am confident that the refund will eventually be issued, it is frustrating to have to follow up on this for months. I hope THY's service departments will see this and address the issue. This has been a confusing experience for me.