Hi Beata,
I don´t think buying a smart phone from the supermarket was a good idea. If you got a receipt you could try returning it. As long as it´s not a food they´ll take it. If not then you can get an ¨Phone Repair Service¨ You can get CPR or Cell phone Repair to help if you live near South Everett, Lynnwood, Woodinville, and seattle-university. There are other phone Repairs too if CPR doesn´t, or can´t help you. You can also try AT&T. Or if you have a friend that can help, I suggest you go to them.
Bye Beata!