I can only see cashed files and cannot see files just uploaded to the server.
I upload my clients updated .html files to NZWebIt's host's server. I use Cute FTP to upload them. Then I can see the new files sitting on the server.
However, when I use a browser to see them, the old files show.

The new updated .html files do not show. Does this mean I'm looking at cashed files?
They are not cashed on my computer because I have cleared the cache and all other offline content.
This problem persists on other computers and also different browsers.

So I presume my clients just see old content after I've uploaded the changes too.
Whenever I change the file, update it or delete it from the server, I still see the old file only. Even if it in no longer on the server.
After approximately 14 hours I can then see the new files I uploaded. I am using NZWebit as a host for my client’s websites.
My Host will not help to solve this.

I don’t want to change hosts if possible as I’d have to shell out hosting for all my clients hosting.
What is the solution to this problem? How can I see changes immediately after uploading an .html file?