Hi Jyasin, firstly I'm not trying to insult you or anyone else, but I think its important that a few things are understood.
- Microsoft are very rarely on here if ever. they are certainly not going to do anything about an issue from a forum. the proper channels must be used to get a problem fixed.
- I promise you regardless of what you think, this problem is fairly small. its not trivial, but just not as widespread as you might think. when I took my phone for repairs, they mentioned they had issues with the mic, but not the same as mine. regardless it was mentioned that it was still a relatively low number of handsets with the issue. its not like they sold 100 units and 90 came back, it was more around 3-5 as an example. (numbers just as indicator)
- with the majority of manufacturers you must take the product back to the place of purchase for repairs. this is how the world works and while it is slowly changing for some manufactures, it is the certainly the procedure for nokia/Microsoft phones at this point in time. buying from an 'online retailer' also known as 'potential dodgy online shop' is 100% at your own risk! you could have bought a stolen phone! they are no doubt not an authorised seller of the products. they should offer you a warranty and you should return it to them. simple as that :) I bet you bought it from the 'online retailer' cause they were cheap (don't worry I do this too, but when things break they end up in a draw or the bin).
if you want the 'apple experience' please go and buy an iPhone. you will be happier!
in order for anyone who wants to move forward and have their phone fixed, please call Microsoft, explain your situation and have the phone returned for repair. I did this through the retail shop that I walked into and bought my 930 and got my phone replaced in 3-5 days.
wishing you all the best of luck with this problem, its unfortunate... but that's life. people make mistakes :)