Premium deleted my songs

[user-removed]

I have had premium for about 4 or 5 monnths now, and have been VERY happy. HOWEVER, I recently was listening in offline mode because I was in the woods and there was no service, and something exteremely problematic occurred. ALL of my 3,000 or so songs were deleted, and i could only recover them after restarting my Galaxy S4 three times. Yet, when I went into my Spotify app they were no longer downloaded and I could not listen to them. I live in an area with little to no cell phone service which is why I pay for premium so listen offline. I have to travel a few miles to get WiFi to download the music. My question is, is this common for anyone else? Was this a freak glitch or will this happen again, and should I switch music providers? I am a radio DJ as well, so if this is happening to many others I would like to let people know so Spotify can address this, because it is EXTREMEMLY inconvienent for me.

Thank you.