mobile academy

Hi,

Since some time when I use Safari for browsing I am automatically to a website to subscribe to mobile academy.
Exact link: start.mobileacademy.com/?campaignid=159

I already remove all browsing history and cache via settings.
Rebooted the phone, but every time it comes back.
The worst thing is when you refuse, it redirects you to google.

So it's simply annoying that you have to start all over again.

The strange thing is also that this only happens when I am on a mobile network for the internet connection.
This never happens when I am on a wifi connection.

Does anyone know how to stop this?

Thanks in advance for the help.
Kind regards,

Lieven