Step 1: You can send an sms to your service provider to receive the correct settings by sms, once received save them by default. If this does not happen then go to step 2.
Step 2: Follow the instructions to set up your phone:
1. Go to Menu > Settings > Configuration
2. Choose Personal configuration settings
3. Press Options
4. Select Add new and Access point
5. Fill in a Account name
6. Select Access point settings
7. Set Data bearer to GPRS
8. Select Bearer settings
9. Enter GPRS access point (APN);
10. Set Authentication type to Normal
11. Enter User name and Password if requested
12. Back * 3
13. Choose Options and Activate
14. Go Back
15. Set Preferred access point to the access point you just made.
16. Set Default configuration settings to Personal config.
17. Select Activate default in all applications and Yes