Constantly Locked out of Account

Hi,

1 of my licensed users is constantly being locked out of their account. This happens once every week or 2, Adobe CS have been absolutely useless in resolving this, it's been ongoing for over 3 months. They claim it's due to multiple incorrect PW attempts & reset it each time but this is not the reason this happens as the password is manually entered with care each login. This is causing major disruption to my my business & takes Adobe 3 days to solve each time. The number provided to call Adobe for assistance is invalid as it has no option for Creative Cloud/Adobe Sign support & I'm finding it impossible to get this issue resolved. The error message on login is: We experienced problem with Adobe login. Please try again. Is anyone here able to offer some assistance with this? Thank you