http://www.howtogeek.com/218851/how-to-enable-always-on-vpn-on-an-iphone-or-ipad /
Problem people is that apple is really doing this on purpose to match the silent privacy agreements they made, basically to make some guys rely on the feature which fails and exposes them, the link i provided is a legitimate way of creating ALWAYS ON VPN mode on an iPhone, and that is ONE and ONLY way for corporations to make use of constant encryption.
Basically it involves in setting up a "Supervised" profile while you are setting up a new iPhone
type
You need to use IKEv2 type of security, its was built for mobile devises, it reconnects better when there is loss of internet (subway tunnel in and out) and is extremely well encrypted, supports AES 128, AES 192, AES 256 and 3DES ciphers
1. To set this up you need Apple Configurator installed on your Mac computer, yes you need Mac computer to do this, you cannot do this on PC.
2. Disable Find My iPhone
3. plug it in, open the Apple configurator, name the phone, and switch on "Supervision"
4. preparation will wipe the iphone you will need to back it up, later you can restore it without any problems, it will also download an entirely different iOS version, not the usual one you get.
5. Now you need to set up an Always On profile, follow instructions in the link to make new profile.
etc