Bandwidth Limit Exceeded Error Solution
1. Log into WHM.
2. Click the "Limit Bandwidth Usage" link. Select the domain or account username for the account that is over its bandwidth limit. Click the "Limit" button. Raise their bandwidth limit and click "Change".
Click on "upgrade/downgrade account" link and upgrade Bandwidth exceed account to higher package.
Note1: Upgrade/downgrade account does not takes care of the bandwidth error instantly. After you upgrade your domain to higher bandwidth package from your reseller WHM you will still have to do "Limit Bandwidth Usage" for changes to take affect instantly.