Contacts can be duplicated when the import is done without the ID column. These contact can not be deleted or removed, but can however be moved and hidden from the user.
The idea is to create a dummy Customer and assign all the duplicates to this customer, and then deactivated that Customer.
Go to Customers and add a new customer. You are free to name it anything, but a recommendation would be something in the line that that makes sense or that can be remembered in future. See example below.
The next step would be to download all the existing contacts. This is found on Insight underneath Settings -> Imports -> contacts imports.
Once complete, open the file.
The first thing would be to assign all duplicates to the Dummy Customer by use of the dummy customer's Code. In this example REMOVE
After all duplicates have been assign to this customer. Save As the file as something else to ensure you have a back up of the list that you currently have.
Open up Skynamo on insights, go to Contact imports and select the new edited file.
After you completed the import, you will find that the dummy customer has a long list of contacts assigned to it.
The other customers should not have any duplicates any more.
You can now deactivate this customer to hide it.
This does not however delete the contact, if you were to download the Contact list All the duplicates will still be present, assigned to the dummy Customer.