so i'm a new seller on ebay and i haven't had any problems so far. There was an international bidder and since i was new, i decided how hard could it be and decided to ship to their country. what i didn't count on was that the customs would be more than the shipping charge and so i emailed the buyer after shipping the item. now they're blaming me and saying that i shouldn't fool them and that there's no seller like me. i replied back that they should have expected custom charges and stuff but that means i paid for all the shipping and customs because they refuse to pay me back. what should i do?