I would maybe just cancel the sale and then ask MM to reconsider the negative trust. I'd also remove your retaliatory feedback as it definitely won't help your situation.
How I see it from reading the thread, the op put in some good effort in creating those collectibles and does not want to just bring the thread down. If they are targeting bitcoin collectors, then it should not be marketed as trustworthy, nor should the buyer be encouraged to use them to receive bitcoins.
If it was marketed purely on sentimental value there may have not been any disconnect during the conversation.
- Jay -