Where do I stand?

[heatered]

I bought a table and 4 chairs from habitat 5 months ago. One of the chairs has sagged. Habitat can't replace because they are discontinued (they still do them but different coloured legs, but can't replace with that because their system won't allow!) they have offered a £30 refund (chairs are £85 each!) or we can send all 4 back and get a full refund which I don't want to do partly because of the hassle involved.

Are there any options I can legally suggest? I expected the chairs to last longer than 5 months.

You have the right to a repair or replacement. However, Habitat can choose which you get. You can't force them to repair.

If they can't repair them or offer a replacement you can reject them for a full refund or keep them and have a price reduction.

Note that they cannot refuse a replacement unless it is impossible, or the cost of replacing is disproportionate compared to repairing. "Computer says no" is not a good enough reason for refusing a replacement. If you are happy to have the different coloured legs, I would push hard for that.