Having had some of my written material "borrowed" by people on occasion, I have seen that there is often confusion between copyright and trademarking.
Copyright is the right to copy, disseminate, reproduce, publicly perform etc and share original work. You don't have to pay for it, you don't even have to apply for it. As soon as you create a piece of original written work (with some exceptions) you own the copyright to it, and no-one can reproduce or use it without your permission. The © symbol is used to remind people that a piece of work is original, or reproduced with permission.
A common writers trick to prove they own the copyright to original work is to send a copy of the work in a sealed envelope to themselves. When left unopened, the postmark serves as proof of the date of creation, and is admissable in court.
Trademarking is totaly different. You can apply for a word, phrase or symbol to become a trademark, and if successful it has the ® next to it. You have to apply for this, and there is a fee. Not all trademark applications are successful. (you can't, for example, trademark the word "and" because then people would need your permission to reproduce it. Still, McDonalds recently tried to trademark "Mc" and attempted to sue a restraunt owner called Mr McSomething. Thankfully there were unsuccessful.)
As soon as you produce original work, you own the copyright to it, and can sue anyone who uses it without your permission. The Bid Fair lot are quite right in that they own the copyright to their own work. However, I wouldn't hold your breath on the legal action, sueing for breach of copyright is expensive and difficult, and nobody in their right mind would go to court over £2.99. Still, it IS their work and I'd be cheesed off too if I was them!
-Philip