Like everything they say, "several days" was off the wall. Still FAIL.
This is from an incident report I filed.
Thank you for contacting developer support. I understand that your app, recently failed certification/Store WACK for unsupported API. I am sorry to hear this, but will be happy to assist. As Derrick mentioned while an app may pass local WACK successfully, The local WACK tool does not test the store policies only the technical requires of the package. Once you submit your app to the Store issues that did not present before can show in testing. For alternatives to the API, I suggest reaching out to our technical forums which are monitored by MSFT and are an excellent resource.. If you encounter a unique concern in the future, please do not hesitate to contact developer support.
Microsoft Windows Developer Support