Sudden spike of Data usage in one day (~6Gb)

[Acw7]

Hi community,

I've been activiely using spotify almost every day, with extreme stream quality set. i rarely download albums and i always make sure it never downloads on mobile data. Each month i use around 5-6gbs of data from streaming. 

yesterday spotify ate up almost 6-7GBs of my data in one day, i did not have it activiely running before sleeping yet when i woke up today i get a notification saying i've hit my data cap so i checked my usage, this also meant it was using my mobile data whilst i was asleep!!! 

I have cleared cache/data, unistalled and reinstalled spotify, But i want to know why this may have happened and if there are any methods to prevent this from occuring again.

Attached is a screenshot of data usage and detailed data brakdown.

Thanks.