Hello,
As a freelancer who has been screwed so many times by the publishers, I can understand you very well. When any publication shows the first signs of an oncoming demise, it is the freelancers who first get the shaft. My only surprise is to see how our situations are similar. I'm living and working in Turkey, and I was expecting to see writer's rights better protected in England. Now I see, wherever you work, freelancer has no rights.
One of the main problems is the big delay between actual work and payment. By the time you get your first payment, you end up having been submitted material for 2-3 more issues. So even if they pay you regularly, they will always be owing you some good money, and for that money's sake, you'll continue to work. A vicious circle.
I'm sorry to say I do not recommend freelancing to anyone, anymore... When someone offers me some freelancing work, I run out of the office screaming, unless the offer comes from a very very trustable company.
Greetings from Istanbul, Levent