...In my experience it is much better to write to American Express using the secure messaging facility on the website. Then you can print and save their confirmation. Email creates accountability.
The
printing part is key. The correspondence about my (former) DL AmEx disappeared from the secure email area, and I had to find the printout promising EQMs on my card at a certain threshold. After sending it to AmEx, they STILL denied me! I had to contact Kevin Pinto at Delta to get it fixed. Left a very bad taste in my mouth for AmEx...