RE: Integration fails with "document already exists"

The error indicates the document exists in system - check SOP10100 and SOP30200 table of GP company database if there the order still exits in database :

select * from sop10100 where sopnumbe = 'Order number'

select * from sop30200 where sopnumbe = 'Order number'

This should confirm if you delete actually deleted the orders.

Cheers!