Sony India — complaint against service center

i purchased sony xperia z1 on 2013 december it went well on that days but on 2015 march when i charged the phone it was not getting charged so i decided to show mobile in sony authorized service center in bangalore the service center name was "R LOGIC TECHNOLOGIES PVT LTD RAJAJINAGAR BANGALORE" they told me that the issue was MOTHER BOARD COMPLAINT and they told me that it will cost 12500 to change it. On hearing that i decided to change mother board and they collected the mobile usually for hardware problems it will take 7 days to solve the issue but they hold my mobile for more than 25 days but i show patience to get solve the issue. they given back my mobile on march 2015 but on april 2015 the phone showed same problem i feel sad and went againt back to them they told me that same problem persist after replacing mother board also i have given my mobile to service center to solve the isssue they have taken 35 days to return the mobile when they returned the mobile the sim tray was lost. but on june 26 the phone again showed the same problem in charging then i again went to them but they treated me very harshly and they waited me for very long time. i am very unhappy regarding the service and their treatment to customers. even though they treated me very badly i have given to them for solving this issue due to the 12500rs which i have already paid for solving this problem