Twyford Windows

I replaced all my windows and the front door with them back in 2012 and the initial experience was excellent. Unfortunately, back in November 2018 I noticed condensation inside one of the Frech doors and contacted them to get the glass replaced under the 10 year guarantee cover. After insisting on the phone and sending repeatedly photos of the glass over email, one of their staff members came along in March 2019 to see the damaged glass. By then there was also another window with condensation, so after looking at all of them they concluded that it was a manufacturing defect from their supplier and told me they will contact the supplier for the replacement of all damaged and "soon-to-be-damaged" glasses. That is the last I have heard from them as they no longer pick up the phone when I call for updates. It is now June 2019 and I am stuck with a set of "presumably defective" windows. I may need to fund the replacement myself and take them to court to get my money back.