Cannot fix problem

Since last year I have a ping noise on my Renault Sandero(2013 model). Everytime I have to take it to dealership to have a look into the matter and everytime I get the car back, the problem is not resolve. This is pathetic service. Why must it takes almost 7 months to resolve a problem. I personally will never buy a Renault again because of the service they render to customers. I wonder why they have a customer care if they are doing nothing, or technical personnel if they cannot sort out the problem.The consumer act state clearly if repairs are carried out it must be in a reasonable time,right,7 months, you are a joke