Bad service - does not come back. Car with extended warranty is still at garage after 76 days.

Presently we have 3 Renaults. Our Captur has been at Renault Paarden for more than a week. It has an extended warranty. They replaced the battery last week and we had to pay. Did not solve the problem and it is now more than 7 working days. I spoke to the desk, the service manager as well as the general manager Robbie. I then send messages to Renault service desk and tried to phone and speak to people there. No joy. They said they will return to me in 10 minutes and no joy.