Bad service

I love my car, but this is my first and last Renault I will ever buy. It is nearly three months and I am tired of their empty promises. My vehicle went in for a service I reported a problem with the water light when I made the booking, confirmed the problem when I took the vehicle for the service. Only to leave the garage and have the exact same problem 10 minutes from the garage, plus the service light is now on. How was my car serviced if I now have additional problems. The worst is that they just do not care.