Free to choose your repairer
According to the legislation, each insured user is totally free to choose his/her repairer. Insurers are obliged to explicitly inform their members of this possibility (which is rarely done).
Indeed, this Hamon law, in effect since 2015, is meant to protect the insured users from non professional practices of some insurers. They put their business interests first, to the detriment of clients' ones, by favoring low cost interventions instead of security and quality.