As with many things there are multiple ways to view many events. In hindsight were you subjected to ‘salesmanship’ or a form of pressure even that being reliance on their apparently faulty computer matching system? From your posts that is what seemingly happened.
Accepting the business’ viewpoint is sometimes the right thing to do, but not always. There is a mismatch of ‘power’ between a trusting customer and a bonus seeking salesperson (concept to be taken broadly) to make a point, even though the customer could with enough personal confidence, just walk away.
As you posted, there was a disparity between Forty Winks computer recommendation and that from the bedding company’s ‘match’. For myself, that would be enough of a data point to cause a lack of trust in the sales tool and thus their response to your claim.
Regardless that you had the opportunity to ‘test’ it in store it remained inappropriate considering your initial ask. While ‘the computer’ and the salesperson seemingly ignored that should not be a defence, excuse, or reason to avoid customer satisfaction and importantly responsibilities under the ACL in spirit as well as just in the letter of the law.
I hope whatever outcome you have is satisfactory to yourself, and whether you take it further is your personal decision. You probably have much to think about from the differing views posted here.
Have a good holiday, and when you have an acceptable mattress a relaxing and comfy new year.
