My experience with Hays tells me.....

That they are not one of the agencies, that really look out for their contractors.

The term cowboys and crooks come to mind.

When the market is quite buoyant, they are a little bit more friendly, but otherwise if you don´t want do what they want, they will drop you like a hot potato!!!

Apart from that they are unreliable in terms of communications.

That´s why any email from hays, doesn´t even get to my inbox but is directed to /dev/null.

Having freelanced in the IT industry for the past 15 (fifteen) years, the UK agencies are generally amongst the worst (sorry to say, but that´s true!!!)

best experience I have had so far is with Germans and Swiss.

But Hays (but that may just be my experience, so totally subjective!!!) is an agency to stay away from!!!