This is very bad selling and you're probably right, that the seller did not receive the price they wanted at auction, and more's the point, does not know how to set an auction, that is, to start it for the lowest amount they are happy to receive, then even with one bid, they cannot be disappointed with the outcome.
No one can force the seller to post a winning item.
Did you pay for the item? Cancelling for out of stock reason, will refund you, and they will get a damaging defect on their account. You can leave appropriate feedback, but do not mention any refund, that can be cause for removal of feedback, just something like very disappointed seller did not honour the sale.
@rocketdog2