If you bought the postage from ebay,then look to cancel it,and either buy the correct postage on ebay,or take your parcel,"once you have created and placed your own buyer address/label on it" to to your local post office who will weigh the package and charge you the correct price over the counter for it,and ask for tracking if you want that to,although the size of the package may well include a barcode reference tracking number.
To void a an ebay label.
- Select Selling in My eBay, or select Orders on the Seller Hub Overview page.
- Select Postage Labels on the left-hand side.
- Select Actions next to the label you'd like to void, and select Void Label.
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