Amazon return duplicated

Hi everyone,
so I started to notice that some customers have duplicated return requests and I have even seen three return requested for one ordered item. Having not taken much interest in this previously I started to question, so if there are 3 return labels that are available under one order and I am liable for the return postage costs am I paying for all three?
I also noticed that the returns labels that are generated all state Carrier picked up the package, I know this is not true as when you track all three only one has been dispatched.
So I am charged at point of customer requesting return or at point of customer dropping the parcel. I cannot seem to find the section on Amazon that will direct me to see the costs taken out for this automated return service. Any help will be apricated regards Richard. Chigwell Satellite.