Samsung.com store is managed by Samsung (i assume) as it's owned by Samsung.
Samsung Experience Store is not managed by Samsung (not directly I would assume even if it's branded everywhere as Samsung) as they don't own them - I believe Apple are the only ones that own & manage their stores.
Samsung presence in telco/other stores is not managed by Samsung as they don't own them.
The fact that a physical store confirmed they have the product on stock, has nothing to do with Samsung.com not having it anymore - I suspect they all work with stocks - some stocks are higher, some are lower, some sell faster, some sell slower, etc. - which I believe causes this type of situations in which you have put an order which for whatever reason is taking longer to complete, than you going to a physical store that has the product in stock.