an ISP systems user has stolen all our content
 

My wife's domain expired (mistake) and was bought by some who wanted us to pay him to get it back - the site is still live and they have also kept all the content and style sheet - We can live with the mistake of letting the domain expire but the content is just ou tof order, plus its selling a DVD and could now be used to STEAL people money. We need help as it is hosted with ISP systems?

ISPsystem.com does not provide webhosting, we are provide software for hosting (ISPmanager control panel), for get you data back you need ask your hoster support.

The IP address resolves to a computer owned by ISPSystems
so it means either the owner of ISPSystems (or one of his employees)
or it's a customer
or you've been hacked

I can provide your company with the URL if you like and you can check yourself - Do provider cover for phishing websites then ? Is there anyone who going to take this seriously ?

Yes, there is separate subdivision beside ISPsystem which provide hosting.

You should write about this incident to abuse @ ispserver.com (see information whois on IP-address) and department, which works with complaint you will answer in workday.
In the letter you need report domain name and IP address which places this content and essence of your complaint and URL link to this forum.