htaccess file changing to "allow from all"- 404 error

Hi everyone,

This is my first time on here- i am going to pre-warn you about my lack of technical knowledge!

I have had an issue repeatedly over the last few months and i am hoping that someone might be able to point me in the right direction to fix it.

My website is on WordPress 4.3.1, running Nova theme.
Every 3 weeks or so, when i visit any of the subpages of my website (e.g. contact us etc), i get a 404 error. I have called the web hosting company (crazy domains…. don’t get me started!!), and they tell me that my htaccess file keeps getting changed to “allow from all”. When they change it back to the correct script the website is fully functional again, but reverts back to this same problem in a matter of weeks.

Would appreciate any advice you might be able to offer. Please remember i’m a bit of a simpleton when it comes to web banter so you may need to break it down for me!

Thanks so much in advance for your help ??

Cheers!