I have a client in Wisconsin that was previously hosting a website with excel.net--they also have internet through excel.net.
Because excel.net web hosting doesn't support PHP email, I migrated their site to hostgator, changed the DNS credentials, and the new hostgator-hosted website appears as expected everywhere--EXCEPT when accessed through an excel.net-provided internet connection. When a visitor on an excel.net internet connection loads my client's website, the old web site appears and typing the url for pages in the new website returns a 404 error.
I can no longer access the old hosting account by FTP and have changed the DNS credentials to the ones provided by HostGator. What loophole am I missing? How can I enable excel.net users to access the HostGator-hosted page?
And how can an internet provider alter DNS credentials for their users?