Bad customer service

Back in May we had fly nets installed by the company Alurea in Altkirch (68). In early June we found that they didn’t close properly, essentially making them useless. We informed the company, who told us they would inform us when someone would be in our area (30 mins from their company) to look at the nets. Now 2 months later, several phone calls and an email later, we have had no visits from Alurea and find they are on holiday till the end of the month. As the summer will then be almost over and we will have little use for fly nets, does anybody have any names of consumer protection bodies/useful suggestions on how to proceed?