By way of update on this, i decided to wait until the 15bd was up. I just figured there was nothing they'd do until that was up, so thought it made sense to wait that period out, and have a stronger argument to put to them, knowing i'd done as they'd asked, and waited patiently. So, after the 15 bd period expired, i called eBay to ask for an update. After telling me they'd heard nothing from UPS, and what felt like some frustration on their side at the lack of progress from UPS, the following business day, they called back to tell me they'd be refunding me the full amount. The money arrived in my account a couple of days later. I got the full amount, including the fees i'd have paid if the sale had gone ahead. i.e. they decided (rightly) my loss was the amount the buyer originally agreed to pay. I'd say this is pretty impressive on eBay's part. They made me wait for it, but probably realised that this wasn't going away, and that under the CRA '15, they didn't have much of a leg to stand on, so just thought it was best to settle and make me whole, which was the result i wanted, without quite as much pain/arguing/back-and-forth as i feared.
It just goes to show, if you're in a similar situation: be polite, and stand your ground. And ask for advice here on OF. Thank you all, and have a great weekend.
John.
EDIT: it also shows just how exposed to delivery firms we are, even if signed for, and insured (as presumably insurance wouldn't have paid out here, given the intended delivery service was 'technically' completed? would like members' thoughts on this, actually). If this was a private sale here, for example, and i was receiving back something from a sale that didn't go according to plan, i'd have been stuffed ...and so it shows we
must insist on a delivery service that ensures it is the
recipient who is to sign for the package, and not any Tom, Dick or Harry who happens to be within arm's length of the deliverer.