Sony Ericsson W910i Mobile — poor aftersales service

i purchased your W910i(red) mobile from "Paragon dep.stores." Thane,on 6/05/2008 . it was working allright for few days but later it developed some problem with the software.It was given to the service centre at Thane (Ccom Services,F/11.Eternity Mall,Teen hat naka,Thane-west)they rectified the problem but they took very long ,almost 2 weeks for that.Last month I had some problem with the keys(buttons) and there was dust in the display which was to be cleaned so I gave my mobile to the same service centre on 25th August 09.again they took very long (15 days) to return it on 12th sept.09.my mother collected it from the centre.and charges were Rs.1685/- I feel it is too much.they did not give me the replaced defective parts. my mother could not check it as she is not aware with all the functions. when I checked it at home I realised that there is still problem with the display of the instrument and we decided to return it to the service centre for rectification.We gave it back on 15th sept.09.They said they will give it back within 2 days.After a few days I got a call from them that there is a crack in the display and again i need to bare the expences for that. I was really worried because I am a XII th std.student and I had already spent for the expensive model(Rs.15000/-),again I spent for the repairs(Rs.1685/-) then my father spoke to them they said they will call him back but they didnot do that.after that we are following every day we speak to diffrent people but at this moment also we do not know the status of my phone and I am having great problem without a cell as I need to communicate a lot.I am really frustrated about the services. and when I spoke to other users of sony ericson it was found that 99% people are not happy with the services of sony ericson.I feel the higher management system should look in to the matter and do something about this as you may lose your valuable customer due to these reasons.( Ist receipt no.185, 2nd complaint no. 9412 dated 15/09/09)