Consumer Redressal

I would like to complaint against the Micromax ltd. I bought one hand set A72 and within a warranty the handset lost its both incomming and out going speaker, hence i submitted the same to Micromax Service center at 6th Block Jayanagare on 9th Nov. they told me it will take maximum 20 days to get it rectified, Howver till today 19-12-2013 i have not received any answer from them, infact i mailed them several times also spoke in phone, they only say that it will take another 10-15 days, even today they say the same thing. I am really harassed mentally and also it is very inconveniance to live without mobile or with borrowed mobile please help.