How to minimise use of cellular data

[jrh2254]

I've got all cellular data use switched off on my phone as my sky sim is constantly flipping in/out of WiFi/cellular  using vast amounts of my monthly data. One month I used all my data and found this was the cause! In particular use of Facebook when I was at home and supposed to be on WiFi !! 
Hence I switch on cellular when I am out for specific apps. Do others have the same problem and how did you fix the issue ? I only have 3gb allowance with sky which is plenty for my usage.  

[Highlinder]

@jrh2254Have you tried to run the broadband test to see if it picks up any faults when you notice that you are being dropped on to mobile data?

Have you re-started your router recently?

[jamesn123 · Accepted solution]

@jrh2254 

Switch off WiFi Assist on your phone it will stop your device switching to mobile data while on WiFi.

[jrh2254]

Thanks - eventually managed to find the option in mobile service in settings. Was looking for something called cellular but could not find this !