DissertationHomework review: totally disgusted! 1

I contacted DissertationHomework and asked them to review my work. I was 100% sure that there were mistakes so I asked these guys for help. I sent them my work and all the necessary information. They replied within two or three hours that they did not find any mistakes and that they had the same result. That was strange that they completed everything so fast. I spent two days on my work but these guys checked everything so fast! Anyways I said thanks and paid.
Later when I submitted my work I received a bad grade because of the mistakes. These guys never checked anything, they just took my money and that's all! I'm totally disgusted with DissertationHomework!