Can't play online or offline on android app

[Snowmannn]

Hi guys,

Apologies if this has been posted before, I've tried to have a look, but it seems the problems I'm encountering seem to differ a little from the others I've seen.

I have Spotify Premium installed on Android (Sony Xperia Z2) but it seems everywhere I turn I seem to encounter something preventing the app to work. 

I try to use Spotify online on both Wifi and 4g, and every 4 or 5 songs just won't play. It says the song is playing, and I can change it from pause to play, and even the song progress bar counts up as if it's playing, but nothing.

I have also tried to use Offline Mode to get around this, and after downloading my library of around 1000 songs to my SD card (128GB, nothing else is stored on it), I have the same issue, only a few songs play. The songs that actually play always seems to be a random selection of 20 or so songs.

I've tried clearing cache several times, I've tried logging out, I've tried uninstalling the app and reinstalling, and I've tried a combination of these, and the only thing that has happened is every time I boot the app now, I have to log in again.

I've had premium for about four months now, and I just can't get it to work, does anybody have any suggestions? Anything is greatly appreciated!!