First, delete all access points in your phone. You can do that by going to the settings menu of your phone and going to the 'access points' panel. OR you can go to your phone's web browser and by going to its settings and options, you can access the Access Points.
After deleting, text "SET N5200" and send to 808 then WAIT for your configuration settings. The settings will be sent as a TEXT MESSAGE so better be mindful of your inbox.
Then, when you are going to view webpages, go back to the settings of your phone's web browser and make sure you select 'Smart' or 'Smart Internet' as the default Access Point.
>>> Also, if you are going to buy a new phone, make sure you get the 3G one, cause, with SMART's low internet rates, you can use high-speed 3G connection better than GPRS. GPRS is ~48kbps and 3G is 364kbps - 1.5 MBPS. Also, it depends if SMART enables 3G on their servers.