Originally Posted by
richarddd
Sounds as if the way to go is disputing and if there isn't a space to explain sending a secure message. The best dispute choice appears to be "I was charged more than expected".
If you or others have a better idea, please let me know.
I found my post in this thread
https://www.flyertalk.com/forum/34796149-post949.html
I chose the charged more than expected. After submitting I also send a secure email explaining the issue and math and referencing my dispute. They did reply to confirm the credit would stick.