Problems with printing ebay standard envelope labels

[cardhound]

Hi - has anyone else had problems when printing ebay standard envelope labels?  I have been using this service for the last several weeks but today - I had five labels that only partially printed - out of 60 purchased.  The problem was the scan square in the upper right corner which only partially appeared.  When I repurchased the labels, they were okay.  How do I get credit for that? how do I cancel those tracking numbers? I can't find any "help" on ebay. Thanks!