Overcharged 90$ for something i sold!!!! Help

I recently sold a toy set for 70$ shipping was 14$ paid for by the buyer!!! I packaged this item boxed it and sent it on its way! Well actually I went to the post office had them scan my QR code and did it that was for the shipping label ! I then got my receipt and left my receipt has no increased total and on the bottom it says 0.00! I then check my eBay app and I notice there is a fee of like -103 for shipping !!!! I don’t understand I would have never sold an item for a loss and then paid 100 for shipping ! How do I deal with this mess! Sleepless in Seattle!