First, dont' take it personally.
The seller seems to be a fairly large business and perhaps communication between the eBay listers and the stockboys is poor.
Was your payment refunded? If so:
You can take several actions.
If you are offered a Mutual Cancellation, you can refuse it. This would mean that the seller cannot get his selling fees back.
You can leave appropriate feedback. Remember that you are judged on the FB you leave. The most effective FB is calm and factual. "Out of Stock. Fast/slow refund"
You can leave appropriate Detailed Seller Ratings. The normal DSR is Five. The lowest is ONE.
You can decide never to spend money with the company again.
As to the higher price.
He could have sold out of the original stock while you were communicating.
He could have received a new shipment while you were communicating.
Well, it could be that the seller's supplier upped the wholesale price.
He may have realized that the original price did not cover his costs.
He may have realized that the original price was lower than the market would bear. (It is not a good business practice to then refuse sales made at the old price, however.)