Recently I've changed from an iPhone 4 to a Samsung galaxy s4. I've been with 48 for the last year and a half and never had a problem with internet until I changed. Mobile data hasn't worked as long as I've had the s4.

"Welcome to 48. Soon you will receive our mobile Internet settings for your phone. If your phone asks, choose to save settings & use the PIN 0000. Go conquer!"

This is a copy of the message they send me. Mobile data is switched on but still not working. Any suggestion?