Downloaded songs stop playing after 30 minutes when away from WiFi

[rachlawrence333]

Hi there, I have been using premium for about 2 months with no issues at all but now whenever I'm out of my WiFi connection at home it only let's me listen to my download songs for exactly 30 minutes then cuts me off and says I need to go back on line to listen to download songs.... and it seems that I'm only able to listen at all away from home if I start playing a track while still in range of my WiFi to start with... I have done the whole uninstall, reinstall thing and cleared the cache but nothing, getting extremely frustrated and ready to walk away!! Please help