Sony Ericsson Model - W100i, Spiro — in case of replacement

Address:

Ghaziabad, Uttar Pradesh

my cell phone has been giving troubles,like it hanged permanently,keypad problems etc.
each time i submitted it, i got a very bad feedback because the cell phone wasn't repaired properly.or there was fault in that cell
again this time it started giving troubles,but now i don't want it to be repaired for a short period of time,i just want that cell to be replaced as the permanent solution to this problem.so kindly try to understand my problem and change that cell otherwise i am ready to accept money back.
also i think that the cell have some inbuilt problems,that's why it doesn't gets fully well,after repair as well.
so please replace my cell or otherwise i will file a case against your company.
and this not a threat but truely the thing i 'll do if i got a bad feedback from you.