@doau486,
Note: you're not contacting eBay by posting on these boards. They are public forums on which any eBay member can post, and the responders are, like you, fellow eBay members who give voluntary helpful advice and information. (The standard of help is usually well above the type of cut-and-paste help provided by eBay customer service.)
This issue that you've described appears to be endemic on the mobile app or on mobile devices. There is so very much wrong with the mobile eBay version that I doubt very much that this will be fixed by eBay's IT. There is no way to get in touch with eBay IT to report faulty code, and if you contact eBay CS by phoning them, you'll be given sympathetic murmurings and a promise that they will inform the relevant department or that it's being/has been escalated by eBay's IT. All of that is bunkum. Nothing's been escalated, nobody's been informed, and you'll be told that it hasn't been reported before, even if hundreds of people have phoned eBay CS with this exact issue.
You should not allow yourself to be coerced into giving free postage when you did not offer it. (Why should you be out the cost postage?)
If it happens in future, inform the buyer that you listed it with postage, and that on the full version of eBay it is correctly rendered. Send them a screenshot, and advise them that eBay mobile version is very glitchy and displays listings incorrectly in some circumstances.
