I repeat myself, be tough, faced with their scam and poorly done jobs:
There was no end of work.
beware, they can invent that you refused reception and other lies !!
so
action and summons for abandonment of work, because it does not work, outside the norms, with firm recommended notice, bailiff's report, letters, then legal action with application for interim measures, to allow the end of the work and restoration to their fees, and also seek quotes from other companies (several if possible) for repair, and emergency functional compliance
Indeed, these quotes are presented before the courts for interim measures, and then before a legal expert, who will start with these quotes, assessing their seriousness.
My legal expert asked him for such a quote from a company, to copy it into his report, even though I had not asked for a quote !!
It is even difficult to have these quotes, because companies are reluctant to resume poorly done work, but in a current recession, it will be easier for you than for me, almost 10 years ago, expanding.
So fundamental, to assess damages very quickly, with repair quotes, from several companies, because I saw quotes with beautiful errors !!
Do not wait for an action, bailiff's report, registered letter, precise, and if no answer within the short deadlines provided, summons to court with summary proceedings, and lawyer, because the deadlines are not very long, a year for the perfect completion, and often, they promise to lengthen the deadlines, without doing anything good, even breaking more, and making the action of perfect completion invalid.
My stubborn architect understood only before the judge !!
And still on econology, claims Windéo and its annular wind turbine scam !!