Constantly inundated with pop-up/ phishing scam messages!

Hi, wondered if anyone could help. For the past 2 weeks I have been inundated with annoying constant pop-ups/ phishing scams "congratulations you have won........." on my 2 iPads and iPhone! It's got to the point now where I can't use any of these devices!! as soon as I use safari, google chrome, most apps e.g BBC news, BBC sport, etc... It automatically goes to prize/ competition messages and can't click off them. I have not been on any dodgy websites, just news and sport ones I have used for years, to start with it seemed to be only BBC sport app but then soon spread to everything!! It also seemed to happen just after I did the latest software update, not sure if thats connected to the problem?

So far I have:

• Cleared web history (many times)
• Completely erased and reset all device and set up as new iPad/ iPhone.
• Created a new Apple ID, incase it was linked to my original account.
• Made sure pop-up blocker was on in settings.
• Been into the apple shop for help twice, they just did what I had already done. It seemed to disappear when in the Apple shop but as soon as I got home n used them again it was back!
• Tried installing pop-up blocker apps but they didn't work, and most weren't comparable with the iPads.
• Messaged Apple on Live Chat, but they Didn't help, just what I'd already done before.

I am completely lost as what to do next.

If anyone has any suggestions of how to get rid of these awful annoying messages/ pop-ups I'd be very grateful.

Thanks