I'm sorry to hear that, our API would have been temporarily down yesterday evening as our team had restarted the server, but otherwise it should have been online. Was the IP address you had whitelisted the first IP you had added to your account? If so, it can take up to 1 hour for our server to accept connections from your IP address, so this may have caused the connection problem.
Please feel free to contact us privately if you are still having problems with connecting to the API and we can check your account and the API command and response to help resolve that.