I really can't help but IMOif you ordered a specific size and it was written on the contract insist on that for sure . I do agree there are some tolerance issues even with custom mande furniture and so I guess my question is who made this . Usually custom furniture does not come from the basic furniture store . Was this actually custom made or just a choice in a list of choices for this piece ? Big difference between the 2 .

did you maybe pay with american express?

i had a simimlar furniture type incidence.. in this case the love seat was wider than the one in the showroom and as indicated in their description. (i had measured showroom to double check) It was a specific width i needed would not fit as planned, lthough only 1.5 inch difference… store gave me a hard time, wanted restocking fee, said real teak can vary… i clicked amex online, filed a claim and they refunded monies. store fell all overthemselves to pick up. we put outside and they came and got it.. amex is power :)

Ugh. I think I'd definitely push harder on returning the sofa. Offer to pay pick-up/delivery cost but no more. You're going to hate life if you try to make this work.

Check the sales contract as someone else said. See if the dimensions are listed, then you've got ground to stand on. Measure the floor sample (hopefully there is one) and see how far off things are.