DSL-AC88U no internet conection

Hi
I am trying to install a DSL-AC68U on a Green telecom line ( 3.0.0.4_384_21128 )
They have told me to setup the same as BT infinity
user name is ******************.ibn@vodafone.net
I get a good dsl connection but no internet connection
they have confirmed I have correct username and password & said it should be working
any ideas what I can try ?

Thank you
Paul