I have to agree with JOUY31, Goldorak and brunos (and carnarvon). I have had luggage lost on pretty much any airline, and while this is extremely frustrating, you mostly find that there are differences in 'support' when it happens but not fundamentally in terms of how long it takes airlines to find and deliver them.

I too am really curious what leads you to draw the conclusion that your bag actually arrived with you at CDG and was just stuck there for 2 days? Frankly, it is not the most likely scenario. The fact that you mentioned several travel classes also makes me wonder if you were on one or multiple tickets? If the latter it would be useful to know what the "ticket break up" was, in particular as, as you probably know given your frequent travelling, in the case of multiple itineraries on separate airlines (even 'partner' airlines), rescanning is always recommended.

In terms of advice, my recommendation would be that if you have travel insurance you claim through them. It does not mean that AF will be off the hook as the insurance will undoubtedly ask the airline for the claim money back, but they will normally reimburse your full costs within the policy limit without an issue. If you ask the airline, they will reimburse 'reasonable costs' and for a two-days delay, they won't set those very high. I think it is also possible that you get something as a gesture of good will but probably not much and I don't think it will require that you ask, as long as you write to them to tell them of your disappointing experience they will send you whatever is standard for such a case.

Finally, a bit of perspective. Again, I fully realise how frustrating not getting one's luggage on time is. First, while 48 hours is not pleasant, it is very very far from the worst case scenario. Second, as you may have heard, much of Europe suffered some terrible weather over Christmas which resulted in multiple airports being shut down for lengthy periods of time because of dangerous landing conditions, flights cancelled or rerouted to alternative airports, etc. We are not talking one flight or something but thousands and thousands of people affected. Ultimately airlines resources to deal with customer issues are limited, and regardless of your or my status, I do think it would be inexcusable for any airline to not prioritise people whose flights have been cancelled and who were physically stuck away from their families and friends over that period. I'm sorry you feel that your Christmas was 'basically ruined', but while it is obviously not my place to tell you how to feel, all I can say is that I am sure that for your family, the important thing was that you were there with them and that they certainly won't have felt that their Christmas was ruined because they did not get their present or because you looked a bit 'scruffy'.