Data destruction

[SebasK1]

Plan

Premium

Country

Netherlands

Device

Galaxy S7

My Question or Issue

 Hi, I use Spotify mobile and make sure I have downloaded all my songs onto my device when I am in wifi range. However, when I left my house this evening and was listening to my already downloaded songs, I got a message from my service provider that I used up my entire months worth of data. When checking the settings I saw that Spotify had used up several Gb of data in a few minutes.

As I've mentioined, I was only listening to the songs I already downloaded, and even if I didn't I don't understand how or why Spotify will use up this much in such a short time. Can anybody tell me what happened? Thanks!