Hi AlannaS,
If you have an Comany Owned Retail Store near you, you should stop in to ensure your information is up to date on the account. Sometimes if your IMEI is not listed properly on a pre-paid account, you will be unable to use some features. Additioanlly your SIM card may be the issue as well.
You may need to configure the APN settings for your Alcatel phone as well. This is generally found in your settings - Network or Connections.
The APN settings for a Non-AT&T device can be found here: APN Settings