Sounds like you're facing the same issue as I did before. Basically our IPs are blocked. I got it fixed last Friday by obtaining a new IP multiple times, and guess what? I got blocked again today. Perhaps you can try what I did, restart your router and modem to obtain new IP. Check that you've obtained a new one by searching "what's my IP" on Google.

Try this?
They block IP because of suspicious activities, and I think in your case, the system thought someone was trying to hack into your account. But sometimes, we don't even know why, like my case.

If you still can't login, try contacting their customer service through email or facebook. I messaged them on facebook the other day and they asked me to provide them with my details. I didn't follow up after that because I thought my problem was fixed... Oh well, I guess I'll just restart my modem again...