Motorola Solutions — Moto g4 plus front camera issue

Address:

Lucknow, Uttar Pradesh, 226006

I have purchased moto g4 plus from amazon 5 jan 2017. after 10 days use in front camera was full of dust. it happens many times, when i visit to service center, service center cleans front camera and again after 10 days front camera full from dust, service center said display was not proper fit and submitted my mobile. after 15 days service return my mobile with new display but still my problem not resolved. i want to change my hand set. kindly solve my problem asap. Purchase Invoice of amazon.com and service center invoice are attached