No signal, poor signsl

I've struggle with a card machine for more than a month now, they didn't come back to me. I've sent emails, WASAPS, fb messengers, I've called in several times. Just to struggle further. VERY GOOD SERVICE IF THEY XAN SELL A MACHINE TO ME, BUT NOW AFTER SERVICE AT ALL. THE MACHINE DOESN'T WANT TO UPDATE, IT DOESN'T WANT TO CONNECT THROUGH WIFI THROUGH MY PHONE. THE CARD MACHINE IS TERRIBLE AND COST ME A LOT OF CLIENTS.