I don't want to be a Debbie Downer, but you won't get a penny back from them. People with that attitude towards their work and other people's property have the same regard for moral integrity. At least you have the 10%.
If you can get quotes and invoices for putting the stuff right, you could try an online money claim. I'm going through it with a non-paying customer and it's actually pretty straightforward. No idea if I'll actually get the money in the end but it's only cost me a couple of hundred quid, mostly just filling in forms.
I don't want to be a Debbie Downer, but you won't get a penny back from them. People with that attitude towards their work and other people's property have the same regard for moral integrity. At least you have the 10%.
If you can get quotes and invoices for putting the stuff right, you could try an online money claim. I'm going through it with a non-paying customer and it's actually pretty straightforward. No idea if I'll actually get the money in the end but it's only cost me a couple of hundred quid, mostly just filling in forms.