How to turn off(delete) NEW JIRA EXPERIENCE permanently

[Vladyslav Klivasov]

Few month ago I already turned off the "NEW JIRA EXPERIENCE" in profile. 
Today I found that it's enabled again and there is no any possibility to turn it off. 

As I can see there are a lot of:
- Not user friendly behaviour across the NEW JIRA EXPERIENCE
- Needed but in the same time missing functionality like "User Activity stream" 

How can I turn off NEW JIRA EXPERIENCE permanently? 
Is it possible ?

[Nic Brough -Adaptavist-]

Your only option is to migrate to Server, which won't be getting the new experience for a long while (hopefully only after Atlassian fix it so it works or abandon it).  The new ui is now mandatory for Cloud