eBay

Can I block a previous buyer in messaging me ?

I have refunded a buyer the amount she paid and the postage on a item she returned, basically changed her mind on a item , she is now asking for more postage money , as she returned it and it cost her more , she didnt want a printed label as she hadn...

I am selling a item and someone had asked if I post to Australia, does the global service cover there , ?Also will I have to alter my postage amount to a higher amount to cover