Worst customer service

Bought a cellphone, this was giving me problem,so I took it back on the 7th day of purchase. Was told nothing is wrong with it and that's what I get for buying a cheap phone. I logged a complaint with customer service and they got the manage to call me. Than she tells me it's after 7 days and they will need to book it. Clearly she didn't listen to the complaint laid. She promised to call me back and still didn't. I laid another complaint and still noone has called me back. The phone is giving me issues and Ackermans doesn't seem to care about my complaint.