Consumer Redressal

I have issues with my sony mobile phone which I gacve it for repair to Numeric Comunication who is the authorised service center for SONY mobiles in bangalore. I have been to teh service center twice for repairs both the times phone works for 1 days and issue persists again. It was a simple speaker issue firsdt time aftwer repair network issues along with batter dryuig down within 3-4hrs without using it at all and unable to hear from the ear speaker. I got it repaired and now the speaker makes crackling sounds so the person on the other end of the phone also dioesn\'t understand anything. this happened al within 3 months of my purchase. The serivce center is not ready to replace the phone and they are rude as well when trying to resolve this problem. They have damaged my phone and not ready to accept. Please help