The most likely causes for having trouble to logging in are
- You are not using SFTP (but FTP or FTPS)
- You are not using port 1022
- You are using the wrong username or password
- You have used the wrong username and password too many times.
After 10 failed login attempts, you will be blocked for 10 minutes. If you fail 30 times during 1 hour, you will be blocked for an hour. Keep in mind that many clients can try to sign in multiple times using different settings on it's own, so 3-4 wrong connection attempts can in some cases be enough to get blocked.
To overcome this problem, set a new SFTP password in the control panel and make sure all your settings are correct (SFTP, port 1022 and the correct hostname, username and password!)