Extreme data usage while on WiFi and/or offline

[heyjaypay]

I have noticed in the last couple months that Spotify has been eating up my data like no other app on my Samsung s6. I never stream music using data because I either listen on WiFi or download music for listening offline, so imagine my surprise when I looked  at my data usage and found that Spotify has chewed up 300Mb of my 2Gb/month data plan. All of the data used is foreground data, but I restricted background data anyways thinking it would help. The next month I payed special attention to make sure I was connected to WiFi before streaming music, but it was to no avail as Spotify again used 250Mb of data for no apparent reason. I am completely baffled and upset that spotify is using my precious data when I am 100% sure I am using WiFi or playing downloaded music. Any advice or solutions to this problem would be appreciated.

Edit: Just checked my data usage and not even two days into my cycle and spotify has already used 11Mb of data.

[user-removed]

Try turning off the mobile data from the phone settings or swipe down from the top of the phone then find and tap the data button off.

[heyjaypay]

Turning off data is the obvious "solution" to using data, but I need my data on for other apps that I use on my phone. Constantly turning on and off my data when I want to listen on Spotify is time consuming and annoying. 

[user-removed]

Do you have offline mode switched on in spotify settings.