Cannot Activate a New Receiver - DirecTV

DirecTV sent me an HR-44 receiver to replace my old HR-33. I am trying now to activate the new receiver. The information on the TV screen says that you can activate in two ways: 1) at or 2) at 800-388-6597.

I have tried the first method with three different browsers, but I get the error: "If you think this is an error, please contact us". The "contact us" is a link, which goes to a support page, which says: "Oops! That page can't be found. No luck ....

So then I tried the phone (multiple times), but only get a fast busy signal. Every "Contact Us" link on the DirecTV website goes to the "Oops!" page. I have no idea how to contact someone to help activate my receiver. Any suggestions?

This question, "Cannot Activate a New Receiver," is about DirecTV channels, programming, equipment, and sports.