I work at NEXT part-time alongside my studies - you wouldn't believe how often large furniture orders get messed up. Recently we've had a load of outdoor table and chair sets retuned for being non-waterproof
Who did you talk to about your bed, if it was the online guys they're awful - no help at all. If you haven't already, ring customer services on 0333 777 8000, they are, in fairness, normally very good and helpful. Failing that, go into your local branch, ask for the manager, and get them to call customer services in-store, it's funny how much more lenient they'll be with a store manager on the other end of the line