After waiting 3 months, fancy new mattress was delivered today. All good, took the wrapping off, put it on the bed and discovered it's a Kingsize rather than the double we ordered (yes, I checked the original order email). AIBU to insist they change it over for the double despite us having unwrapped it? (Full disclosure it's a tiny room and we just bought a new double bedframe, so I reaaally don't want to have to rebuy a Kingsize bedframe which takes up half the bloody room). AAAARGH.