Premio cell phone

Today i went to purchase my son a premio s82 phone before i bought the phone i asked one of the ladys hows this phone meaning ok they have experience about this phone she was so nice convincing me to buy the phone saying the phone is fast and good and can play games.when i got home gave it to my son and he was happy for 5mins i asked whats wrong he said the phone takes forever to go onto the internet it said in the phone case its 4g finding out its 3g i geuss wrong stand was in the display case and im very unhappy i just want my money back and il put more money by and purchase a new phone.and what i picked ul if the phone is 100% charged and i restart it the battery is on 40% again.this is my number to be contacted on ***.