Unable to Email Readded Contacts (Contact Import Unsuccessful)

Unable to Email Readded Contacts (Contact Import Unsuccessful)

When importing a file containing contacts, there is a huge percentage of contacts that are listed as "readded". When creating a list with this file, it is preventing us from sending a campaign to these contacts.

We have been unable to successfully create a new list in over 3 weeks.

Calling customer service has been unsuccessful and we are losing business due to being unable to use these tools in nearly a month.

Is anyone else experiencing this issue?
Can someone from Zoho explain why this is happening?
Is there a resolution so we can continue to use this tool?