T-Mobile has the perfect data-centric plan for Walmart customers — unlimited data at 4G speeds, unlimited text and 100 minutes of voice for just $30 . T-Mobile’s latest “unlimited” plan for pre-paid Walmart and T-Mobile.com customers seem to be perfect for someone like me: text and data heavy users who rarely use their phones for voice calls. It offers 4G speeds (HSPA+ with theoretical speeds of 42 Mbps) for the first 5 GB of data and drops down to 2G speeds for the remainder of the month, .... read me.