Replacement for faulty item - please advise

willis

I bought a small kitchen appliance from a well known high street store. It has now broken and is within the guarantee so as long as they confirm it's faulty they will do a replacement. However, the product I bought is no longer available so I have to choose another one up to the same value. They don't sell the appliance for this price, so my only option is to pay extra as I have been told I can choose a more expensive replacement and pay the difference.
Surely they should replace like for like? Ie: the same brand with roughly the same specifications? I can't remember whether I bought it when it was on sale or it was just a good price, but the amount they have offered me will not buy a comparable product, not even if I choose the very cheapest brand and model.

The product has broken through no fault of my own so I don't see why I should pay extra to get a comparable replacement. I don't want a refund as it seems I couldn't buy a replacement elsewhere for the amount they'll refund me.

What should I do?
Thanks