Best answer by rikkster
Usually a data block is requested by the customer. If your plan did not include data, then chances are there's no data block. If at some point you added a data block, this should show in your self serve account in the plans and add-ons area.
With mobile data enabled, try toggling airplane mode on and off, sometimes this gets data to work. If not and again with mobile data enabled, try turning off the phone completely, wait a minute or two and turn the phone back on and see if data works. If that doesn't work, you may have to call customer service for further assistance. Dial 611, choose option 6 for tech support.