Your Ad-Center account can be Suspended for a variety of reasons.
Suspended simply means that your login is disabled, sales are not affected.
Policy suspension: Due to breaches in Ad-Center policy or lack of response to policy, your account will be suspended. Please check your email and contact your Account Manager.
Inactivity suspension: Due to 30 days of inactivity, your account will be suspended. Please contact your Account Manager to get started again.