Smarty network access point settings

You are missing the major point - The phone is not picking up three, Smarty’s parent network, so even if you had the settings, it still would not work on Smarty, as the phone is not picking up the Three network. 

As this is the Smarty community forum, we are customers, just like you, we don’t work for Smarty. 

I would suggest one of two things :

1, Start a webchat with Smarty, which is available from 08.00 - 20.00 seven days a week.

2, As Smarty is owned by Three, it may be worth popping into a Three store to see if they can help you. 

EDIT : I have just looked at the link you sent, which of course goes to the Argos website, and I note that in the description of the phone, Argos themselves say the phone can be used on EE, O2 and Vodafone. There is no mention of Three anywhere in the phone’s description.