Glazing company refusing to fix leaking roof

Hi Had glass roof fitted 7 yrs ago. Called company out from day 4 as it has leaked. They have replaced the glass but still not worked and it still pours water in. They are refusing to sort the issue but I have countless emails and they even agreed face to face they would finally sort this when I met them. But the owner has given back word and is refusing to speak with me. This is a large national company. In your opinion what do you believe are my options bar legal?