Amazon.com, Amazon Blocked our Amazon account and held a huge amount of money as hostage Internet

We are an online seller and sell using various channels.
We have been selling items on amazon for the past 3 years. Recently we received an email that our account is blocked and suspended with no more explanation. Also our funds is held hostage. Amazon is holding our funds and we are not able to communicate with them. We are getting automated responses with no clear direction as when they will give us our money. Also there is no customer support number for sellers. At this point our account is shutdown and a huge amount is held hostage with amazon. Amazon is not giving us a timeframe as when they will return our money or if they intend to refund. The behaviour of amazon is highly unprofessional and the sellers are treated with no respect. We are trying to get in contact with amazon for the past 1 week, but no success.