Ring broke and they refuse to fix it

We bought a wedding ring in August and they said that they will resize my ring. A month later the ring snapped at bottom. We took it back and were told that when they resized it the ring was thinner. If they knew it would not last if they resized the ring why didn't they tell us. Now they refuse to fix it at their cost and now have sent us a quote to fix it that costs more than the actual ring. It seems they taking us for a ride and it's a money making racket. The ring didn't even last a month. Surely when they resize it they would know ok it will work and last. Now I'm sitting without a wedding ring and they won't take the responsibility of fixing it since it's still new.