IcelandAir review: Denied boarding

This is a long and complicated story. Back in May, 2023, I booked two separate flights on Icelandair through Expedia. The first, which was to leave Seattle to Reykjavik on August 19, 2023, the second was from Reykjavik to Oslo the following day (August 20). Both flights were for business class seats. However, at Seattle, we were denied boarding because our passports were not in compliance (less than 3 months before expiration). While I understand that this is a governmental issue, Icelandair was fully aware of our passport information, since I had to enter it on their website. They could have simply told us well in advance that we needed new passports. As a result, not only could we not board the Seattle to Reykjavik flight, we obviously had to miss our Reykjavik to Oslo flight. Furthermore, when we arrived at the airport, before the passport issue was discovered, we were told that our Business Class seats for the Seattle to Reykjavik flight had been downgraded to Economy. Obviously the seats we paid for had been filled, even if not by us. I also strongly suspect that the business class seats on the Reyjkavik to Oslo flight were also sold, meaning that Icelandair wasn't out any money. When I complained to Icelandair, they said that I had to go through Expedia, since they booked the flight, but everytime I contacted Expedia they referred me back to Icelandair. To add insult to injury, when we applied for passports on an expedited basis (we were booked on a cruise leaving Norway on August 26th), I went ahead and booked two new flights on Icelandair. Including the return trip from Reykjavik to Seattle on September 11th, I spent over $7000 on airfare with Icelandair. Despite this fact, all that Icelandair offered me was to refund the airport taxes and fees for the Reykjavik to Oslo flight, but they said I had to go to Expedia to collect. When I contacted Expedia, they said it was a matter for Icelandair. It was a classic runaround.