Yes they are a scam site.
They sent me a completely plagiarized paper and when I asked for a refund they continued to ignore me and send me revised papers that had nothing to do with the assignment outline, had extremely poor English and was repetitive.

I continued to ask for refunds and they continued to make excuses for why I wasn't eligible for a refund.
So I escalated the claim with paypal and then AffordableWriting.net sent me an email threatening me.

See below:

theresearchersmail@gmail on behalf of AffordableWriting.net (support@affordablewriting.net)
Sent: Saturday, 18 August 2012 10:34:01 AM
To: *******
We will not be entertaining your calls, emails and chats.
Now we will fight for the money on dispute that you filed.
We will make sure that we win it and also, we will inform your University about the scam you have causing in the Market.
Regards,Customer Services

SO NOT ONLY WILL THEY SCAM YOU AND TAKE YOUR MONEY, BUT THEY WILL ALSO THREATEN TO INFORM YOUR UNIVERSITY.
PLEASE SHARE THIS AROUND AND DON'T LET THEM HURT AND SCAM ANYONE ELSE

Unfortunately they are not a UK or USA based company as they claim. They are in India. And I wouldn't be surprised if it was just one guy running the show as they seem to have no experience what so ever in writing papers. Its just a copy and paste job from the internet.

I've escalated the claim with paypal and I guess that's what has upset them, but I'm not going to let my money go to waste on a scam.

Just be careful, don't let them get anyone else and spread the word about their website.

Just a quick note. I sent the below email to them. And an hour later they had refunded my money and settled the dispute via paypal.

Lesson learnt, if you are overwhelmed with study, ask for an extension... Don't ever think that there's some ligit website out there that can help you.

The email:

"If you attempt to inform my university or use my personal information in any possible way I will take you to court.
It is a breach of your privacy policy and goes against the terms and conditions of your website.
The email you sent below was completely unprofessional and extremely hurtful to your case.
I have gathered all the information on your company including IP address and I am ready to take this case to a small claims court and sue you."

Thank you karen_criticalproof for your advice :)