Lenovo — mic problem with lenovo k33a42

Address:

Bhopal, Madhya Pradesh, 462011

I had purchased lenovo mobile (K33a42) in mid june 2017 and within 4 weeks mic was not working properly. I went to the service center and they kept it for 2 weeks saying that part is not available and after 2 weeks service center returned the phone after replacement of malfunctioning part.
But the problem is not yet solved, still the person on other side (During call) says i can't hear ur voice properly and i had to keep keep my hand near mic for proper transfer of voice. I always had to use my both hands whenever i am talking on my lenovo mobile.