SURVEYNOW NOT PAYING!!!

I received $12.50 on 7 September to my PayPal account and they specify that the money will be deposited into my account in 1 to 4 business days. It has been 6 business days and I have still not received it. I sent them 2 emails and made a complaint on their website to query the issue, but I have not received any feedback from them. Now when I try to log into their website I get a 404 error for the last 3 days. I have been doing reviews for them for about 6 months to accumulate $12.50 and now it seems as though they are reluctant to engage with me. I won't be doing any more reviews for them until I receive my money. I'm extremely disappointed with their customer service.