If you go in to the lead and click on the "Request a call back" button, the rated people guys will try to contact the customer. If they can't contact the customer you'll normally get a credit for the lead,
Alex if you go on to the lead that you brought and you should have 3 options in white boxes just press the report lead and then it will take you through a series of questions you then have to answer the questions and it will check if you can get your money back.
Be mindful if you have requested a call back you have to wait 24 hours before reporting the lead.
Also rated people will check with the customer and then make a decision on whether you get your money back if they cannot get in touch with the customer then you have to wait 3 days.
Hope this helps mate