Nokia 7210 supernova
Costumer Care not attending properly

Few days ago I face problem in my cell. My nokia 7210 S was restarting I go for Nokia care they said my cell display is damage dew to water and and it cost 500-600 Rs. But my cell never drop in water or any liquid damage. after this I get my cell to dealer from where I buy my cell he update cell software and my cell work fine. After a week I face same problem and Nokia care not attending me properly. Many other people have same problem which I face. Please tell me what should I do now