This question can be answered by carefully studying 99papers.com's refund policy. You can find it in the footer of the website.
Having read their refund policy, I still had some questions as it seemed to be written in vague terms for me. There's no single case where it's said how much percent exactly you will get back. They say you're entitled to a full refund if a double payment has been made or two identical orders have been placed.
If they are late, they promise a full reimbursement. There are many things that can make it difficult to reimburse the full amount paid for the paper. The way the money back policy was written is the thing that I found most annoying. They try to convince you that this won't happen in each case and that there is nothing to be worried about. But, I don't want any assurances. I just want to know the clear cases in which my money will be returned.
I was happy with the quality of the paper, regardless of how vague their money-back policy. This service has a great website design and friendly support agents. If I ever have to use a writing agency again, I am 100% certain I will.