Well... first off, are you sure? ;-)
Our private proxies only allow access to 5 websites; Facebook, Google, Instagram, YouTube & LinkedIn (and their subdomains). Are you trying to reach one of those 5 websites?
Try to use the proxy in a browser (FireFox for instance) and visit one of those 5 websites. If it works you know the proxy is working fine and the problem lies somewhere else.
If you tried everything but still believe your proxies are down please send a message to support and include the browser/software you are using and the website you are trying to reach.
We'll get you up and running in no time!