*****ing my rewards

I have been earning Membership Rewards on my Amex for hte past 7 years. All of a sudden they claim that the exact same spending is not eligbale. I have read all the documents and it is indeed eligable.

My query has been running for a month and now I hear it is closed. No feedback, no reasons, nobody calling me back despite promises to do so.

Why is my rewards being ****** from me all of a suddent?