Lewis Furniture - Awful service

I bought a stove from Lewis, it did not even last 6 months. I informed them it was broken. They never came out. I stopped paying the account and that got their attention very quickly.
They then sent people out to check in December.
I then paid the account December. They promised that they will have it fixed as soon as the places open in January.
They never sent anyone out to fix it. Two months later they then sent out people regarding my account that's in areas. I told them I will pay the account if they fix the stove or replace it. They left and promised they will sort it out. Thesame story a few months later an no one came. My credit record have been messed up due to this and refuse to pay the account until the stove is fixed.
Can any one please assist. It's now again 9 months and I am still waiting for them to fix the stove. They harassing me for payments but is not keeping to their side.