Seller Shipping Fee Higher than Buyer Pays

[morgansknobuniques4u]

Is anybody having issues with the shipping charges? The last two I had I have been charged more for the label tan the buyer paid in calculated payment. The first time I was refunded the over pay. old there was a problem. This time I sent message through Facebook message.  Told that the USPS charge included my fees. Funny since fees are taken out first. Then the postage was paid. Is there a reason it is so difficult to get a number to talk o someone?