Have you set APN? Check this
Login to Self-Care -> Subscriptions, and click "Request for APN settings". Once you save the SMS, the APN is automatically set.
You can also set the APN setting manually. Please check the Access Point Name (APN) setting of your phone is set to "webe".
To check and change, please follow the steps below.
Settings > More > Mobile networks/Cellular networks > Access point names OR Settings > Mobile networks > Access Point Names. Click "Edit the Access Point Names" and change the APN to webe. Leave other fields as-is and Save the new setting. Reboot your phone if necessary.
iOS models: Settings > Mobile Data > Mobile Data Network OR Settings > Cellular > Cellular Data Network. Tap the Access Point Name field and change to webe. Leave other fields as-is and Save the new setting. Reboot your phone if necessary.
If all these done and still not active, you better check with livechat team.