Postage Label Not Showing

[emma--k]

I've purchased a Royal Mail postage label through ebay for a sold item, this was done on my phone - and would normally store the label as an option to go and 'reprint' it from the desktop computer attached to our printer.  As usual, the item was marked as dispatched with the purchase of the postage label, however it's not showing up at all in the 'Postage Labels' section (where all other sold and postage paid items are listed).  I have the option to 'print another label' when going back through the listing itself, which is fine but would mean having to pay again for postage.  I would therefore need to know how to cancel the original postage payment first.  That isn't showing up in Postage Labels.  Can anyone please help?