TuneIn? My phone only works as an iPod.

[SodaStereo]

My phone is Galaxy Ace 2 SGH-T599V and when I want to use TuneIn only works with a wireless network and does not work with mobile internet signal. The only way that TuneIn works is, for example, tuning any radio station in my house and continuing with the same radio station without being able to change it when I am out of it. If I try to change of radio station, TuneIn does not work. Any ideas about this? Thanks