I've also been getting many calls about processing these duplicate magazine invoices.
What is happening is many are getting invoices resent by the supplier. When they process them through the XChangeIT document it throws up two "cannot archive" messages for every repeated invoice they try to bring in. Since the message says to contact POS we're getting many calls. For example it is not uncommon for clients to bring in a dozen or so invoices that are already there, that's a dozen error messages x 2 = 24. That's 24 button clicks, most people give up after about 10 and assume their XchangeIT system is locked in a loop then call us.
If this happens to you, it is not locked just keep trying on the next invoice.
We have notified XchangeIT of the problem, that the error message is wrong and are waiting for a fix from them.