Actually I ended up getting helped! I stuck with it and they escalated it again, saying that in fact it was a bug and said they'd send me my missing stones along with all relevant data to the devs to help fix it! Can't say how happy I was in the customer service by the end. It's rough getting the dismissive auto responses but you can get through to someone who wants to (and can) help with some persistence. Very happy ending indeed.
If you get the attachments you will find the geode in your inventory. It's only a graphical bug, probably due to a problem with the geode icon.