You need to go into the router management pages and put in the correct settings. You have to make a PPPoE connection and the username is firstname.lastname@example.org and the password can be anything you want if your router needs one.
I don't have this router but going by the instructions here
it should be fairly straight forward to set up. All the setting should be populated automatically when you connect with the exception of the setting I gave you.
If you have changed or put in any settings other than the PPPoE and account name etc I gave you I would carry out a factory reset of the router and start again following the instructions to the letter.
Make sure you are connecting by Ethernet before trying to connect by wireless.
Have you tried connecting your phone by wireless in case it's a problem with the computers connection?