I don't understand why this site is so full of warnings against Oxbridge Essays: they're expensive yes, but you get what you pay for in this world. Like WRT said, you can get a refund through your credit card company if you didn't get your essay which means that OxE would lose out by not sending it to you. On top of that they still have to pay the writer, so by not sending it to you they've actually lost a large proportion of that £300.
I've had nothing but good experiences with them: they do cost a bit but I found their customer service to be great and the essays were on time and good quality.