Lenovo — complaint on smart phone A706

Address:

Prakasam, Andhra Pradesh

Dear sir, I purchase lenovo A706 in the month of may 2014 from the purchase onwards the mobile is not working properly.i gave my mobile in lenovo service centre at hyderabad they taken 20 days for resolve the problem, same problem will arrise now the gave mobile after changing the mother board after completing one week now it is not working properly plz rectify my proble by exchanging my phone with s850