There are no "Send" or "Clear" buttons on their contact page - they are do-dos it seems.... Have you tried emailing them? ...
I wouldn't mind them not having a landline but it's very unusual that they don't answer their mobile phone. Do they have voice mail so you can leave a message? Have you tried emailing them?
I never believe online testamonials but noticed that they are registered.
This is on the bottom of their contact page:Registered for what? Where did you see that?
I'd always be a little dubious about dealing with a company who don't put a physical address on their web site. They also use a UK agency to hide their domain ownership information. Alarm bell number 2.
Leo