Insanely high data usage problem?

[#1]

My usage recently went from 30GB/mo to over 350GB. After a lot of investigation it turned out to be an update on my Sky HD box.This renamed a 'feature' that downloads films they think I may like in the background. I had this turned off, but the update renamed it to Options->Customise->Enable Push on Demand.and turned it back on. It is supposed to run in the background, but seems to run all the time placing a heavy load on my connection. It still seems lto be downloading a lot of something so I am thinking of enabeling parental controls on the router so I can turn off all internet access except in the evening when I may want iplayer. I also have to check out what my smart TV is doing to my downloads.

[#2]

Sorry for the slow replies guys. I have been out the house a load lately because the internet got so bad I struggled to load web pages. And I thought I would check out pokemon go as I got a new phone. I am still working on the internet problem but what seems to be pulling through is if I stay off the internet for a prolonged amount of time (like 3 days in a row) then by the 4th day I can get on the internet like its normal but if I use too much again then boom it returns back to its slow state so I am trying to manage it by using as little as possible over time and hope it settles down. And also I do have a smart TV and the other week (when it started happening) is when youtube added their streaming button to youtube so maybe its something to do with that. I think I will limit the smart TV's access to the internet as its rarely used after about 11pm anyway.